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Мы можем использовать оператор `in` следующим образом:\r\n\r\n```javascript\r\nconst person = { age: 25, gender: 'female' };\r\nif ('name' in person) {\r\n console.log('У объекта есть свойство name');\r\n} else {\r\n console.log('У объекта нет свойства name');\r\n}\r\n```\r\n\r\nЕсли свойство `name` есть в объекте `person`, то в консоли будет выведено сообщение «У объекта есть свойство name», в противном случае выведется сообщение «У объекта нет свойства name».\r\n\r\nТакже мы можем использовать метод `hasOwnProperty()` объекта `person`:\r\n\r\n```javascript\r\nconst person = { age: 25, gender: 'female' };\r\nif (person.hasOwnProperty('name')) {\r\n console.log('У объекта есть свойство name');\r\n} else {\r\n console.log('У объекта нет свойства name');\r\n}\r\n```\r\n\r\nРезультат работы этого кода будет аналогичен предыдущему.\r\n","votes_up_count":3,"votes_down_count":0,"created_at":"2023-04-04T14:59:58.622Z","user_id":319860,"category_slug":"javascript"},{"user":{"id":506962,"email":"kypulko_egor@bk.ru","first_name":"Егор","last_name":"Курилко","telegram":"Egor_Kurilko","full_name":"Егор Курилко","removed":false},"question":{"creator":{"id":104929,"email":"feycot@gmail.com","first_name":"Nikolai","last_name":"Gagarinov","telegram":"","full_name":"Nikolai Gagarinov","removed":false},"category":{"id":2,"title":"JavaScript","slug":"javascript","questions_count":852,"locale":"ru"},"tags":[{"id":571,"slug":"js","name":"JS"},{"id":633,"slug":"javascript","name":"JavaScript"}],"id":2665,"answers_count":2,"slug":"kak-proverit-svoystvo-v-ob-ekte-js","state":"published","title":"как проверить свойство в объекте js\r","created_at":"2023-03-27T06:54:43.230Z","details":null,"best_answer_id":2162,"related_stacks_count":5},"id":3529,"state":"active","body":"Существует и другой способ проверки наличия свойств, например [Object.hasOwn()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn). \r\nЕсть разъясняющая статья от Хекслета - [здесь](https://ru.hexlet.io/qna/javascript/questions/chem-otlichaetsya-object-hasown-i-object-prototype-hasownproperty).","votes_up_count":1,"votes_down_count":0,"created_at":"2024-04-12T14:37:51.187Z","user_id":506962,"category_slug":"javascript"}],"relatedQuestions":[{"creator":{"id":363630,"email":"a.agaphonov@ya.ru","first_name":"Человек-Молекула","last_name":"","telegram":null,"full_name":"Человек-Молекула","removed":false},"category":{"id":2,"title":"JavaScript","slug":"javascript","questions_count":852,"locale":"ru"},"tags":[],"id":1359,"answers_count":1,"slug":"kak-sdelat-drag-and-drop-javascript","state":"published","title":"Как сделать drag and drop 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Мы можем использовать оператор `in` следующим образом:\r\n\r\n```javascript\r\nconst person = { age: 25, gender: 'female' };\r\nif ('name' in person) {\r\n console.log('У объекта есть свойство name');\r\n} else {\r\n console.log('У объекта нет свойства name');\r\n}\r\n```\r\n\r\nЕсли свойство `name` есть в объекте `person`, то в консоли будет выведено сообщение «У объекта есть свойство name», в противном случае выведется сообщение «У объекта нет свойства name».\r\n\r\nТакже мы можем использовать метод `hasOwnProperty()` объекта `person`:\r\n\r\n```javascript\r\nconst person = { age: 25, gender: 'female' };\r\nif (person.hasOwnProperty('name')) {\r\n console.log('У объекта есть свойство name');\r\n} else {\r\n console.log('У объекта нет свойства name');\r\n}\r\n```\r\n\r\nРезультат работы этого кода будет аналогичен предыдущему.\r\n","datePublished":"2023-04-04T14:59:58.622Z","upvoteCount":3,"author":{"@type":"Person","name":"Aleksey"},"url":"https://ru.hexlet.io/qna/javascript/questions/kak-proverit-svoystvo-v-ob-ekte-js#answer-2162"},"suggestedAnswer":[{"@type":"Answer","text":"Существует и другой способ проверки наличия свойств, например [Object.hasOwn()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn). \r\nЕсть разъясняющая статья от Хекслета - [здесь](https://ru.hexlet.io/qna/javascript/questions/chem-otlichaetsya-object-hasown-i-object-prototype-hasownproperty).","datePublished":"2024-04-12T14:37:51.187Z","upvoteCount":1,"author":{"@type":"Person","name":"Егор Курилко"},"url":"https://ru.hexlet.io/qna/javascript/questions/kak-proverit-svoystvo-v-ob-ekte-js#answer-3529"}]}}</script><div style="--container-size:var(--container-size-lg);margin-top:var(--mantine-spacing-xl);height:100%" class="m_7485cace mantine-Container-root" data-size="lg" data-strategy="block"><script type="application/ld+json">{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"position":1,"@type":"ListItem","item":{"@id":"/qna","name":"Вопросы и ответы"}},{"position":2,"@type":"ListItem","item":{"@id":"/qna/javascript/questions","name":"JavaScript"}},{"position":3,"@type":"ListItem","item":{"@id":"/qna/javascript/questions/kak-proverit-svoystvo-v-ob-ekte-js","name":"как проверить свойство в объекте js\r"}}]}</script><div style="margin-bottom:var(--mantine-spacing-xs)" class="m_8b3717df mantine-Breadcrumbs-root"><a style="--text-fz:var(--mantine-font-size-sm);--text-lh:var(--mantine-line-height-sm);white-space:normal;color:inherit" class="mantine-focus-auto m_849cf0da m_f678d540 mantine-Breadcrumbs-breadcrumb m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-size="sm" data-underline="hover" href="/"><div style="color:inherit" class="m_4451eb3a mantine-Center-root"><svg xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-home-link "><path d="M20.085 11.085l-8.085 -8.085l-9 9h2v7a2 2 0 0 0 2 2h4.5"></path><path d="M9 21v-6a2 2 0 0 1 2 -2h2a2 2 0 0 1 1.807 1.143"></path><path d="M20 21a1 1 0 1 0 2 0a1 1 0 1 0 -2 0"></path><path d="M20 16a1 1 0 1 0 2 0a1 1 0 1 0 -2 0"></path><path d="M15 19a1 1 0 1 0 2 0a1 1 0 1 0 -2 0"></path><path d="M21 16l-5 3l5 2"></path></svg></div></a><div class="m_3b8f2208 mantine-Breadcrumbs-separator">/</div><a style="--text-fz:var(--mantine-font-size-sm);--text-lh:var(--mantine-line-height-sm);white-space:normal;color:inherit" class="mantine-focus-auto m_849cf0da m_f678d540 mantine-Breadcrumbs-breadcrumb m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-size="sm" data-underline="hover" href="/qna">Вопросы и ответы</a><div class="m_3b8f2208 mantine-Breadcrumbs-separator">/</div><a style="--text-fz:var(--mantine-font-size-sm);--text-lh:var(--mantine-line-height-sm);white-space:normal;color:inherit" class="mantine-focus-auto m_849cf0da m_f678d540 mantine-Breadcrumbs-breadcrumb m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-size="sm" data-underline="hover" href="/qna/javascript/questions">JavaScript</a><div class="m_3b8f2208 mantine-Breadcrumbs-separator">/</div><p style="--text-fz:var(--mantine-font-size-sm);--text-lh:var(--mantine-line-height-sm);white-space:normal;color:var(--mantine-color-dimmed)" class="mantine-focus-auto m_f678d540 mantine-Breadcrumbs-breadcrumb m_b6d8b162 mantine-Text-root" data-size="sm">как проверить свойство в объекте js
</p></div><style data-mantine-styles="inline">.__m__-_R_eub_{margin-bottom:var(--mantine-spacing-xs);}@media(min-width: 36em){.__m__-_R_eub_{margin-bottom:var(--mantine-spacing-xs);}}</style><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:space-between;--group-wrap:wrap" class="m_4081bf90 mantine-Group-root __m__-_R_eub_"><style data-mantine-styles="inline">.__m__-_R_deub_{width:100%;}@media(min-width: 36em){.__m__-_R_deub_{width:70%;}}@media(min-width: 75em){.__m__-_R_deub_{width:75%;}}</style><div class="__m__-_R_deub_"><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><h1 style="--title-fw:var(--mantine-h1-font-weight);--title-lh:var(--mantine-h1-line-height);--title-fz:var(--mantine-h1-font-size)" class="m_8a5d1357 mantine-Title-root" data-order="1">как проверить свойство в объекте js
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href="/qna/javascript/tags/js"><div style="--badge-height:var(--badge-height-sm);--badge-padding-x:var(--badge-padding-x-sm);--badge-fz:var(--badge-fz-sm);--badge-bg:var(--mantine-color-default);--badge-color:var(--mantine-color-default-color);--badge-bd:calc(0.0625rem * var(--mantine-scale)) solid var(--mantine-color-default-border);cursor:pointer" class="m_347db0ec mantine-Badge-root" data-variant="default" data-size="sm"><span class="m_5add502a mantine-Badge-label">JS</span></div></a><a class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/qna/javascript/tags/javascript"><div style="--badge-height:var(--badge-height-sm);--badge-padding-x:var(--badge-padding-x-sm);--badge-fz:var(--badge-fz-sm);--badge-bg:var(--mantine-color-default);--badge-color:var(--mantine-color-default-color);--badge-bd:calc(0.0625rem * var(--mantine-scale)) solid var(--mantine-color-default-border);cursor:pointer" class="m_347db0ec mantine-Badge-root" data-variant="default" data-size="sm"><span class="m_5add502a mantine-Badge-label">JavaScript</span></div></a></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:flex-start;--group-wrap:wrap;margin-bottom:var(--mantine-spacing-xl);font-size:var(--mantine-font-size-sm)" class="m_4081bf90 mantine-Group-root"><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:wrap;margin-inline-start:auto" class="m_4081bf90 mantine-Group-root"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-calendar "><path d="M4 7a2 2 0 0 1 2 -2h12a2 2 0 0 1 2 2v12a2 2 0 0 1 -2 2h-12a2 2 0 0 1 -2 -2v-12"></path><path d="M16 3v4"></path><path d="M8 3v4"></path><path d="M4 11h16"></path><path d="M11 15h1"></path><path d="M12 15v3"></path></svg><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root" data-inherit="true">3 года назад</p></div><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:wrap" class="m_4081bf90 mantine-Group-root"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-user "><path d="M8 7a4 4 0 1 0 8 0a4 4 0 0 0 -8 0"></path><path d="M6 21v-2a4 4 0 0 1 4 -4h4a4 4 0 0 1 4 4v2"></path></svg><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root" data-inherit="true">Nikolai Gagarinov</p></div></div><div role="link" tabindex="0" style="cursor:pointer"><button style="display:block;width:100%" class="mantine-focus-auto m_87cf2631 mantine-UnstyledButton-root" type="button" aria-label="Присоединяйтесь к нашему Telegram-сообществу"><div style="background-color:light-dark(var(--mantine-color-gray-1), var(--mantine-color-dark-6));margin-block:var(--mantine-spacing-xs)" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root"><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:flex-start;--group-wrap:wrap" class="m_4081bf90 mantine-Group-root"><div style="--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;margin-inline-end:auto;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-brand-telegram "><path d="M15 10l-4 4l6 6l4 -16l-18 7l4 2l2 6l3 -4"></path></svg></div>Присоединяйтесь к нашему Telegram-сообществу</div></div></button></div><h2 style="--title-fw:var(--mantine-h2-font-weight);--title-lh:var(--mantine-h2-line-height);--title-fz:var(--mantine-h2-font-size);margin-block:var(--mantine-spacing-xl)" class="m_8a5d1357 mantine-Title-root" data-order="2">Ответы</h2><div style="margin-bottom:var(--mantine-spacing-xl);padding:var(--mantine-spacing-lg)" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true" id="answer-2162"><div style="--group-gap:calc(1.125rem * var(--mantine-scale));--group-align:stretch;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><div style="--stack-gap:var(--mantine-spacing-md);--stack-align:stretch;--stack-justify:flex-start;font-size:var(--mantine-font-size-h1);font-weight:lighter;text-align:center" class="m_6d731127 mantine-Stack-root">3<a style="color:inherit" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/qna/javascript/questions/kak-proverit-svoystvo-v-ob-ekte-js/answers/2162/vote"><div style="--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-thumb-up "><path d="M7 11v8a1 1 0 0 1 -1 1h-2a1 1 0 0 1 -1 -1v-7a1 1 0 0 1 1 -1h3a4 4 0 0 0 4 -4v-1a2 2 0 0 1 4 0v5h3a2 2 0 0 1 2 2l-1 5a2 3 0 0 1 -2 2h-7a3 3 0 0 1 -3 -3"></path></svg></div></a><div style="--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-check "><path d="M5 12l5 5l10 -10"></path></svg></div></div><div style="--stack-gap:var(--mantine-spacing-md);--stack-align:stretch;--stack-justify:flex-start;width:100%;min-width:0rem" class="m_6d731127 mantine-Stack-root"><div style="margin-bottom:auto" class="m_d08caa0 mantine-Typography-root"><p>Для проверки наличия свойства в объекте в JavaScript можно использовать оператор <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">in</code> или метод объекта <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">hasOwnProperty()</code>.</p>
<p>Например, у нас есть объект <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">person</code> с некоторыми свойствами, и мы хотим узнать, есть ли у него свойство <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">name</code>. Мы можем использовать оператор <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">in</code> следующим образом:</p>
<div style="margin-bottom:var(--mantine-spacing-lg)" class="m_e597c321 mantine-CodeHighlight-codeHighlight" dir="ltr"><div class="m_be7e9c9c mantine-CodeHighlight-controls"><button style="--ai-bg:transparent;--ai-hover:transparent;--ai-color:inherit;--ai-bd:none" class="mantine-focus-auto mantine-active m_d498bab7 mantine-CodeHighlight-control m_8d3f4000 mantine-ActionIcon-root m_87cf2631 mantine-UnstyledButton-root" data-variant="none" type="button" aria-label="Copy code"><span class="m_8d3afb97 mantine-ActionIcon-icon"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" fill="none" stroke-linecap="round" stroke-linejoin="round"><path stroke="none" d="M0 0h24v24H0z" fill="none"></path><path d="M8 8m0 2a2 2 0 0 1 2 -2h8a2 2 0 0 1 2 2v8a2 2 0 0 1 -2 2h-8a2 2 0 0 1 -2 -2z"></path><path d="M16 8v-2a2 2 0 0 0 -2 -2h-8a2 2 0 0 0 -2 2v8a2 2 0 0 0 2 2h2"></path></svg></span></button></div><div style="--scrollarea-scrollbar-size:calc(0.25rem * var(--mantine-scale));--sa-corner-width:0px;--sa-corner-height:0px" class="m_f744fd40 mantine-CodeHighlight-scrollarea m_d57069b5 mantine-ScrollArea-root" dir="ltr"><div style="overflow-x:hidden;overflow-y:hidden;overscroll-behavior-inline:none" class="m_c0783ff9 mantine-ScrollArea-viewport" data-scrollbars="xy"><div class="m_b1336c6 mantine-ScrollArea-content"><pre class="m_2c47c4fd mantine-CodeHighlight-pre" style="padding:0"><code class="m_5caae6d3 mantine-CodeHighlight-code">const person = { age: 25, gender: 'female' };
if ('name' in person) {
console.log('У объекта есть свойство name');
} else {
console.log('У объекта нет свойства name');
}</code></pre></div></div></div><button class="mantine-focus-auto m_c9378bc2 mantine-CodeHighlight-showCodeButton m_87cf2631 mantine-UnstyledButton-root" data-hidden="true" type="button">Expand code</button></div>
<p>Если свойство <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">name</code> есть в объекте <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">person</code>, то в консоли будет выведено сообщение «У объекта есть свойство name», в противном случае выведется сообщение «У объекта нет свойства name».</p>
<p>Также мы можем использовать метод <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">hasOwnProperty()</code> объекта <code style="margin-bottom:var(--mantine-spacing-lg)" class="m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight m_e597c321 mantine-CodeHighlight-codeHighlight m_dfe9c588 mantine-InlineCodeHighlight-inlineCodeHighlight">person</code>:</p>
<div style="margin-bottom:var(--mantine-spacing-lg)" class="m_e597c321 mantine-CodeHighlight-codeHighlight" dir="ltr"><div class="m_be7e9c9c mantine-CodeHighlight-controls"><button style="--ai-bg:transparent;--ai-hover:transparent;--ai-color:inherit;--ai-bd:none" class="mantine-focus-auto mantine-active m_d498bab7 mantine-CodeHighlight-control m_8d3f4000 mantine-ActionIcon-root m_87cf2631 mantine-UnstyledButton-root" data-variant="none" type="button" aria-label="Copy code"><span class="m_8d3afb97 mantine-ActionIcon-icon"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" stroke-width="2" stroke="currentColor" fill="none" stroke-linecap="round" stroke-linejoin="round"><path stroke="none" d="M0 0h24v24H0z" fill="none"></path><path d="M8 8m0 2a2 2 0 0 1 2 -2h8a2 2 0 0 1 2 2v8a2 2 0 0 1 -2 2h-8a2 2 0 0 1 -2 -2z"></path><path d="M16 8v-2a2 2 0 0 0 -2 -2h-8a2 2 0 0 0 -2 2v8a2 2 0 0 0 2 2h2"></path></svg></span></button></div><div style="--scrollarea-scrollbar-size:calc(0.25rem * var(--mantine-scale));--sa-corner-width:0px;--sa-corner-height:0px" class="m_f744fd40 mantine-CodeHighlight-scrollarea m_d57069b5 mantine-ScrollArea-root" dir="ltr"><div style="overflow-x:hidden;overflow-y:hidden;overscroll-behavior-inline:none" class="m_c0783ff9 mantine-ScrollArea-viewport" data-scrollbars="xy"><div class="m_b1336c6 mantine-ScrollArea-content"><pre class="m_2c47c4fd mantine-CodeHighlight-pre" style="padding:0"><code class="m_5caae6d3 mantine-CodeHighlight-code">const person = { age: 25, gender: 'female' };
if (person.hasOwnProperty('name')) {
console.log('У объекта есть свойство name');
} else {
console.log('У объекта нет свойства name');
}</code></pre></div></div></div><button class="mantine-focus-auto m_c9378bc2 mantine-CodeHighlight-showCodeButton m_87cf2631 mantine-UnstyledButton-root" data-hidden="true" type="button">Expand code</button></div>
<p>Результат работы этого кода будет аналогичен предыдущему.</p></div><div class="m_3eebeb36 mantine-Divider-root" data-orientation="horizontal" role="separator"></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:flex-start;--group-wrap:wrap;font-size:var(--mantine-font-size-sm)" class="m_4081bf90 mantine-Group-root"><div style="--group-gap:var(--mantine-spacing-xs);--group-align:center;--group-justify:flex-start;--group-wrap:wrap;margin-inline-start:auto" class="m_4081bf90 mantine-Group-root"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-calendar "><path d="M4 7a2 2 0 0 1 2 -2h12a2 2 0 0 1 2 2v12a2 2 0 0 1 -2 2h-12a2 2 0 0 1 -2 -2v-12"></path><path d="M16 3v4"></path><path d="M8 3v4"></path><path d="M4 11h16"></path><path d="M11 15h1"></path><path d="M12 15v3"></path></svg><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root" data-inherit="true">3 года назад</p></div><div style="--group-gap:var(--mantine-spacing-xs);--group-align:center;--group-justify:flex-start;--group-wrap:wrap" class="m_4081bf90 mantine-Group-root"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-user "><path d="M8 7a4 4 0 1 0 8 0a4 4 0 0 0 -8 0"></path><path d="M6 21v-2a4 4 0 0 1 4 -4h4a4 4 0 0 1 4 4v2"></path></svg><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root" data-inherit="true">Aleksey</p></div></div></div></div></div><div style="margin-bottom:var(--mantine-spacing-xl);padding:var(--mantine-spacing-lg)" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true" id="answer-3529"><div style="--group-gap:calc(1.125rem * var(--mantine-scale));--group-align:stretch;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><div style="--stack-gap:var(--mantine-spacing-md);--stack-align:stretch;--stack-justify:flex-start;font-size:var(--mantine-font-size-h1);font-weight:lighter;text-align:center" class="m_6d731127 mantine-Stack-root">1<a style="color:inherit" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/qna/javascript/questions/kak-proverit-svoystvo-v-ob-ekte-js/answers/3529/vote"><div style="--ti-bg:transparent;--ti-color:var(--mantine-color-indigo-light-color);--ti-bd:calc(0.0625rem * var(--mantine-scale)) solid transparent;color:inherit" class="m_7341320d mantine-ThemeIcon-root" data-variant="transparent"><svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-thumb-up "><path d="M7 11v8a1 1 0 0 1 -1 1h-2a1 1 0 0 1 -1 -1v-7a1 1 0 0 1 1 -1h3a4 4 0 0 0 4 -4v-1a2 2 0 0 1 4 0v5h3a2 2 0 0 1 2 2l-1 5a2 3 0 0 1 -2 2h-7a3 3 0 0 1 -3 -3"></path></svg></div></a></div><div style="--stack-gap:var(--mantine-spacing-md);--stack-align:stretch;--stack-justify:flex-start;width:100%;min-width:0rem" class="m_6d731127 mantine-Stack-root"><div style="margin-bottom:auto" class="m_d08caa0 mantine-Typography-root"><p>Существует и другой способ проверки наличия свойств, например <a style="text-decoration:underline" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwn" rel="noopener noreferrer" target="_blank">Object.hasOwn()</a>.<br/>
<!-- -->Есть разъясняющая статья от Хекслета - <a style="text-decoration:underline" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="https://ru.hexlet.io/qna/javascript/questions/chem-otlichaetsya-object-hasown-i-object-prototype-hasownproperty" rel="noopener noreferrer" target="_blank">здесь</a>.</p></div><div class="m_3eebeb36 mantine-Divider-root" data-orientation="horizontal" role="separator"></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:center;--group-justify:flex-start;--group-wrap:wrap;font-size:var(--mantine-font-size-sm)" class="m_4081bf90 mantine-Group-root"><div style="--group-gap:var(--mantine-spacing-xs);--group-align:center;--group-justify:flex-start;--group-wrap:wrap;margin-inline-start:auto" class="m_4081bf90 mantine-Group-root"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-calendar "><path d="M4 7a2 2 0 0 1 2 -2h12a2 2 0 0 1 2 2v12a2 2 0 0 1 -2 2h-12a2 2 0 0 1 -2 -2v-12"></path><path d="M16 3v4"></path><path d="M8 3v4"></path><path d="M4 11h16"></path><path d="M11 15h1"></path><path d="M12 15v3"></path></svg><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root" data-inherit="true">2 года назад</p></div><div style="--group-gap:var(--mantine-spacing-xs);--group-align:center;--group-justify:flex-start;--group-wrap:wrap" class="m_4081bf90 mantine-Group-root"><svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.2" stroke-linecap="round" stroke-linejoin="round" class="tabler-icon tabler-icon-user "><path d="M8 7a4 4 0 1 0 8 0a4 4 0 0 0 -8 0"></path><path d="M6 21v-2a4 4 0 0 1 4 -4h4a4 4 0 0 1 4 4v2"></path></svg><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root" data-inherit="true">Егор Курилко</p></div></div></div></div></div><style data-mantine-styles="inline">.__m__-_R_4bbdiub_{--carousel-slide-gap:var(--mantine-spacing-xs);--carousel-slide-size:70%;}@media(min-width: 36em){.__m__-_R_4bbdiub_{--carousel-slide-gap:var(--mantine-spacing-xl);--carousel-slide-size:50%;}}</style><div style="--carousel-control-size:calc(2.5rem * var(--mantine-scale));--carousel-controls-offset:var(--mantine-spacing-sm);margin-top:var(--mantine-spacing-xl);margin-bottom:var(--mantine-spacing-lg);padding-block:var(--mantine-spacing-sm);background:var(--app-color-surface)" class="m_17884d0f mantine-Carousel-root responsiveClassName" data-orientation="horizontal" data-include-gap-in-size="true"><div class="m_39bc3463 mantine-Carousel-controls" data-orientation="horizontal"><button class="mantine-focus-auto m_64f58e10 mantine-Carousel-control m_87cf2631 mantine-UnstyledButton-root" type="button" data-inactive="true" data-type="previous" tabindex="-1"><svg viewBox="0 0 15 15" fill="none" 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5.94637 3.84197 6.13523L7.5 9.56464L11.158 6.13523C11.3595 5.94637 11.6759 5.95657 11.8648 6.15803C12.0536 6.35949 12.0434 6.67591 11.842 6.86477L7.84197 10.6148C7.64964 10.7951 7.35036 10.7951 7.15803 10.6148L3.15803 6.86477C2.95657 6.67591 2.94637 6.35949 3.13523 6.15803Z" fill="currentColor" fill-rule="evenodd" clip-rule="evenodd"></path></svg></button></div><div class="m_a2dae653 mantine-Carousel-viewport" data-type="media"><div class="m_fcd81474 mantine-Carousel-container __m__-_R_4bbdiub_" data-orientation="horizontal"><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/programs/js-oop?promo_name=programs_list&promo_position=qna_question&promo_creative=catalog_card&promo_type=card" target="_blank"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">2 месяца</span><span class="mantine-focus-auto m_b6d8b162 mantine-Text-root">·</span><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Для продвинутых</span></div><p style="margin-bottom:var(--mantine-spacing-sm);font-size:var(--mantine-font-size-h5);font-weight:bold" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">ООП на Javascript</p><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Изучите архитектуру и принципы чистого кода на JS</p><div style="margin-top:auto" class=""><div class="m_4451eb3a mantine-Center-root"><img style="opacity:0.8;width:70%" class="m_9e117634 mantine-Image-root mantine-visible-from-xs" src="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NDAxOSwicHVyIjoiYmxvYl9pZCJ9fQ==--84efd2b6854b7000046e9ce06e6be85d38af5ab8/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/JavaScript%20frameworks-cuate.png" alt="ООП на Javascript" loading="eager"/></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:end;--group-justify:space-between;--group-wrap:wrap;margin-top:var(--mantine-spacing-xs)" class="m_4081bf90 mantine-Group-root"><p style="font-size:var(--mantine-font-size-xl)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">от 3 900 ₽</p><p style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Посмотреть →</p></div></div></div></a></div></div><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/programs/frontend?promo_name=programs_list&promo_position=qna_question&promo_creative=catalog_card&promo_type=card" target="_blank"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">10 месяцев</span><span class="mantine-focus-auto m_b6d8b162 mantine-Text-root">·</span><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">С нуля</span></div><p style="margin-bottom:var(--mantine-spacing-sm);font-size:var(--mantine-font-size-h5);font-weight:bold" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Фронтенд-разработчик</p><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Изучите HTML, CSS, JavaScript и React</p><div style="margin-top:auto" class=""><div class="m_4451eb3a mantine-Center-root"><img style="opacity:0.8;width:70%" class="m_9e117634 mantine-Image-root mantine-visible-from-xs" src="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MzcyNywicHVyIjoiYmxvYl9pZCJ9fQ==--2d5cbbf5c3b4a73ae4b2c50632305d78f5872e4d/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Programmer-rafiki.png" alt="Фронтенд-разработчик" loading="eager"/></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:end;--group-justify:space-between;--group-wrap:wrap;margin-top:var(--mantine-spacing-xs)" class="m_4081bf90 mantine-Group-root"><p style="font-size:var(--mantine-font-size-xl)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">от 6 792 ₽</p><p style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Посмотреть →</p></div></div></div></a></div></div><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/programs/js-sicp?promo_name=programs_list&promo_position=qna_question&promo_creative=catalog_card&promo_type=card" target="_blank"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">1 месяц</span><span class="mantine-focus-auto m_b6d8b162 mantine-Text-root">·</span><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Для продвинутых</span></div><p style="margin-bottom:var(--mantine-spacing-sm);font-size:var(--mantine-font-size-h5);font-weight:bold" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">СИКП на JS</p><p class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Навык фундаментального программирования</p><div style="margin-top:auto" class=""><div class="m_4451eb3a mantine-Center-root"><img style="opacity:0.8;width:70%" class="m_9e117634 mantine-Image-root mantine-visible-from-xs" src="https://hexlet.io/rails/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6Mzc2MCwicHVyIjoiYmxvYl9pZCJ9fQ==--9348098e4053d798b6f34bee4ef66947540261e4/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJ3ZWJwIiwicmVzaXplX3RvX2xpbWl0IjpbNDAwLDQwMF0sInNhdmVyIjp7InF1YWxpdHkiOjg1fX0sInB1ciI6InZhcmlhdGlvbiJ9fQ==--5b6f46dacd1af664f27558553a58076185091823/Low%20code%20development-rafiki.png" alt="СИКП на JS" loading="eager"/></div><div style="--group-gap:var(--mantine-spacing-md);--group-align:end;--group-justify:space-between;--group-wrap:wrap;margin-top:var(--mantine-spacing-xs)" class="m_4081bf90 mantine-Group-root"><p style="font-size:var(--mantine-font-size-xl)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">от 3 900 ₽</p><p style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Посмотреть →</p></div></div></div></a></div></div><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/programs/typescript?promo_name=programs_list&promo_position=qna_question&promo_creative=catalog_card&promo_type=card" target="_blank"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" data-with-border="true"><div style="--group-gap:calc(0.25rem * var(--mantine-scale));--group-align:center;--group-justify:flex-start;--group-wrap:nowrap" class="m_4081bf90 mantine-Group-root"><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">2 месяца</span><span class="mantine-focus-auto m_b6d8b162 mantine-Text-root">·</span><span style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Для продвинутых</span></div><p 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style="--group-gap:var(--mantine-spacing-md);--group-align:end;--group-justify:space-between;--group-wrap:wrap;margin-top:var(--mantine-spacing-xs)" class="m_4081bf90 mantine-Group-root"><p style="font-size:var(--mantine-font-size-xl)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">от 3 900 ₽</p><p style="font-size:var(--mantine-font-size-sm)" class="mantine-focus-auto m_b6d8b162 mantine-Text-root">Посмотреть →</p></div></div></div></a></div></div><div class="m_d98df724 mantine-Carousel-slide" data-orientation="horizontal"><div tabindex="0" style="cursor:pointer;height:100%"><a style="text-decoration:none" class="mantine-focus-auto m_849cf0da m_b6d8b162 mantine-Text-root mantine-Anchor-root" data-underline="hover" href="/programs/js-domain-driven-design?promo_name=programs_list&promo_position=qna_question&promo_creative=catalog_card&promo_type=card" target="_blank"><div style="height:100%" class="m_e615b15f mantine-Card-root m_1b7284a3 mantine-Paper-root" 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