path: root/files/ko/web/javascript/reference/global_objects/object/observe/index.html

---
title: Object.observe()
slug: Web/JavaScript/Reference/Global_Objects/Object/observe
tags:
  - 감시 객체
translation_of: Archive/Web/JavaScript/Object.observe
---
<div>{{JSRef}}</div>

<p><strong><code>Object.observe()</code></strong> 메소드는 객체의 변화를 비동기로 감시하는데에 사용된다. 이 메소드는 변화들이 발생한 순서대로 그 흐름을 제공한다.</p>

<h2 id="문법">문법</h2>

<pre class="syntaxbox"><code>Object.observe(<var>obj</var>, <var>callback</var>[, <var>acceptList</var>])</code></pre>

<h3 id="파라미터">파라미터</h3>

<dl>
 <dt><code>obj</code></dt>
 <dd>감시될 객체입니다.</dd>
 <dt><code>callback</code></dt>
 <dd><code>obj</code>의 변경이 일어났을 때마다 호출될 함수입니다. 다음과 같은 인자를 갖습니다.
 <dl>
  <dt><code>changes</code></dt>
  <dd>변경 사항을 나타내는 객체의 배열입니다. 그 객체의 프로퍼티는 다음과 같습니다.
  <ul>
   <li><strong><code>name</code></strong>: 변경된 프로퍼티의 이름입니다.</li>
   <li><strong><code>object</code></strong>: 변경이 일어난 뒤의 객체입니다.</li>
   <li><strong><code>type</code></strong>: 변경의 종류를 의미하는 string입니다. <code>"add"</code>, <code>"update"</code>, <code>"delete"</code> 중 하나입니다.</li>
   <li><strong><code>oldValue</code></strong>: 변경되기 이전의 값입니다. <code>"update"와</code> <code>"delete"</code> 타입에만 존재합니다.</li>
  </ul>
  </dd>
 </dl>
 </dd>
 <dt><code>acceptList</code></dt>
 <dd>감시할 변경의 종류를 의미하는 리스트입니다.  주어지지 않은 경우, 배열 <code>["add", "update", "delete", "reconfigure", "setPrototype", "preventExtensions"]</code> 이 이용될 것입니다.</dd>
</dl>

<h2 id="설명">설명</h2>

<p><code>callback</code>은 <code>obj</code>에 변경이 있을 때마다 실행되며, 모든 변경 사항이 일어난 순서대로 담긴 배열이 전달됩니다.</p>

<h2 id="예제">예제</h2>

<h3 id="Logging_all_six_different_types">Logging all six different types</h3>

<pre class="brush: js">var obj = {
  foo: 0,
  bar: 1
};

Object.observe(obj, function(changes) {
  console.log(changes);
});

obj.baz = 2;
// [{name: 'baz', object: &lt;obj&gt;, type: 'add'}]

obj.foo = 'hello';
// [{name: 'foo', object: &lt;obj&gt;, type: 'update', oldValue: 0}]

delete obj.baz;
// [{name: 'baz', object: &lt;obj&gt;, type: 'delete', oldValue: 2}]

Object.defineProperty(obj, 'foo', {writable: false});
// [{name: 'foo', object: &lt;obj&gt;, type: 'reconfigure'}]

Object.setPrototypeOf(obj, {});
// [{name: '__proto__', object: &lt;obj&gt;, type: 'setPrototype', oldValue: &lt;prototype&gt;}]

Object.seal(obj);
// [
//   {name: 'foo', object: &lt;obj&gt;, type: 'reconfigure'},
//   {name: 'bar', object: &lt;obj&gt;, type: 'reconfigure'},
//   {object: &lt;obj&gt;, type: 'preventExtensions'}
// ]
</pre>

<h3 id="데이터_바인딩">데이터 바인딩</h3>

<pre class="brush: js">// A user model
var user = {
  id: 0,
  name: 'Brendan Eich',
  title: 'Mr.'
};

// Create a greeting for the user
function updateGreeting() {
  user.greeting = 'Hello, ' + user.title + ' ' + user.name + '!';
}
updateGreeting();

Object.observe(user, function(changes) {
  changes.forEach(function(change) {
    // Any time name or title change, update the greeting
    if (change.name === 'name' || change.name === 'title') {
      updateGreeting();
    }
  });
});
</pre>

<h3 id="Custom_change_type">Custom change type</h3>

<pre class="brush: js">// A point on a 2D plane
var point = {x: 0, y: 0, distance: 0};

function setPosition(pt, x, y) {
  // Performing a custom change
  Object.getNotifier(pt).performChange('reposition', function() {
    var oldDistance = pt.distance;
    pt.x = x;
    pt.y = y;
    pt.distance = Math.sqrt(x * x + y * y);
    return {oldDistance: oldDistance};
  });
}

Object.observe(point, function(changes) {
  console.log('Distance change: ' + (point.distance - changes[0].oldDistance));
}, ['reposition']);

setPosition(point, 3, 4);
// Distance change: 5
</pre>

<h2 id="Specifications">Specifications</h2>

<p><a href="https://github.com/arv/ecmascript-object-observe">Strawman proposal for ECMAScript 7</a>.</p>

<h2 id="브라우저_호환성">브라우저 호환성</h2>

<div>{{CompatibilityTable}}</div>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatChrome("36")}}</td>
   <td>{{CompatNo}} [1]</td>
   <td>{{CompatNo}} [2]</td>
   <td>{{CompatOpera("23")}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatChrome("36")}}</td>
   <td>{{CompatNo}} [1]</td>
   <td>{{CompatNo}} [2]</td>
   <td>{{CompatOpera("23")}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>

<p>[1]: See {{bug(800355)}}</p>

<p>[2]: See relevant <a href="https://dev.modern.ie/platform/status/objectobserve/">MS Edge platform status entry</a></p>

<h2 id="같이_보기">같이 보기</h2>

<ul>
 <li>{{jsxref("Object.unobserve()")}} {{experimental_inline}}</li>
 <li>{{jsxref("Array.observe()")}} {{experimental_inline}}</li>
</ul>