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authorPeter Bengtsson <mail@peterbe.com>2020-12-11 18:59:39 -0500
committerPeter Bengtsson <mail@peterbe.com>2020-12-11 18:59:39 -0500
commitd192fb918b0e2aa8869de6dcc59de8464b6e879a (patch)
tree3dc6f395a53be89041c52e9326baf908ffa3f3a6 /files/zh-cn/web/javascript/reference/operators/instanceof
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Diffstat (limited to 'files/zh-cn/web/javascript/reference/operators/instanceof')
-rw-r--r--files/zh-cn/web/javascript/reference/operators/instanceof/index.html14
1 files changed, 7 insertions, 7 deletions
diff --git a/files/zh-cn/web/javascript/reference/operators/instanceof/index.html b/files/zh-cn/web/javascript/reference/operators/instanceof/index.html
index c97b2a72a4..d637cf41e1 100644
--- a/files/zh-cn/web/javascript/reference/operators/instanceof/index.html
+++ b/files/zh-cn/web/javascript/reference/operators/instanceof/index.html
@@ -20,7 +20,7 @@ translation_of: Web/JavaScript/Reference/Operators/instanceof
<h2 id="Syntax" name="Syntax">语法</h2>
-<pre><code><em>object</em> instanceof <em>constructor</em></code></pre>
+<pre class="notranslate"><code><em>object</em> instanceof <em>constructor</em></code></pre>
<h3 id="Parameters" name="Parameters">参数</h3>
@@ -38,7 +38,7 @@ translation_of: Web/JavaScript/Reference/Operators/instanceof
<p><code>instanceof</code> 运算符用来检测 <code>constructor.prototype </code>是否存在于参数 <code>object</code> 的原型链上。</p>
-<pre class="brush: js">// 定义构造函数
+<pre class="brush: js notranslate">// 定义构造函数
function C(){}
function D(){}
@@ -87,14 +87,14 @@ o3 instanceof C; // true 因为 C.prototype 现在在 o3 的原型链上
<p>但是,使用对象文字符号创建的对象在这里是一个例外:虽然原型未定义,但 <code>instanceof Object</code> 返回 <code>true</code>。</p>
-<pre class="brush: js">var simpleStr = "This is a simple string";
+<pre class="brush: js notranslate">var simpleStr = "This is a simple string";
var myString = new String();
var newStr = new String("String created with constructor");
var myDate = new Date();
var myObj = {};
var myNonObj = Object.create(null);
-simpleStr instanceof String; // 返回 false, 检查原型链会找到 undefined
+simpleStr instanceof String; // 返回 false, 非对象实例,因此返回 false
myString instanceof String; // 返回 true
newStr instanceof String; // 返回 true
myString instanceof Object; // 返回 true
@@ -113,7 +113,7 @@ myDate instanceof String; // 返回 false</pre>
<p>下面的代码创建了一个类型 <code>Car</code>,以及该类型的对象实例 <code>mycar</code>. <code>instanceof</code> 运算符表明了这个 <code>mycar</code> 对象既属于 <code>Car</code> 类型,又属于 <code>Object</code> 类型。</p>
-<pre class="brush: js" dir="rtl">function Car(make, model, year) {
+<pre class="brush: js notranslate" dir="rtl">function Car(make, model, year) {
this.make = make;
this.model = model;
this.year = year;
@@ -128,13 +128,13 @@ var b = mycar instanceof Object; // 返回 true
<p>要检测对象不是某个构造函数的实例时,你可以这样做</p>
-<pre class="brush: js">if (!(mycar instanceof Car)) {
+<pre class="brush: js notranslate">if (!(mycar instanceof Car)) {
// Do something, like mycar = new Car(mycar)
}</pre>
<p>这和以下代码完全不同</p>
-<pre class="brush: js">if (!mycar instanceof Car)</pre>
+<pre class="brush: js notranslate">if (!mycar instanceof Car)</pre>
<p>这段代码永远会得到 <code>false</code>(<code>!mycar</code> 将在 <code>instanceof</code> 之前被处理,所以你总是在验证一个布尔值是否是 <code>Car</code> 的一个实例)。</p>