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authorPeter Bengtsson <mail@peterbe.com>2020-12-08 14:40:17 -0500
committerPeter Bengtsson <mail@peterbe.com>2020-12-08 14:40:17 -0500
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+---
+title: Function.caller
+slug: Web/JavaScript/Reference/Global_Objects/Function/caller
+translation_of: Web/JavaScript/Reference/Global_Objects/Function/caller
+---
+<div>{{JSRef("Global_Objects", "Function")}} {{non-standard_header}}</div>
+
+<h2 id="Summary" name="Summary">概述</h2>
+
+<p>返回调用指定函数的函数.</p>
+
+<p>该属性不是ECMA-262第3版标准的一部分.不过, <a href="/zh-cn/SpiderMonkey" title="zh-cn/SpiderMonkey">SpiderMonkey</a> (Mozilla的JavaScript引擎) (查看{{ Bug("65683") }}), V8 (Chrome的JavaScript引擎) 和 JScript(IE的ECMAScript实现)都已经支持了它.</p>
+
+<h2 id="Description" name="Description">描述</h2>
+
+<p>如果一个函数<code>f</code>是在全局作用域内被调用的,则<code>f.caller为</code><code>null</code>,相反,如果一个函数是在另外一个函数作用域内被调用的,则<code>f.caller指向调用它的那个函数.</code></p>
+
+<p>该属性的常用形式<code>arguments.callee.caller</code>替代了被废弃的 <a href="/zh-cn/JavaScript/Reference/Functions_and_function_scope/arguments/caller" title="zh-cn/JavaScript/Reference/Functions_and_function_scope/arguments/caller">arguments.caller</a>.</p>
+
+<h3 id="Notes" name="Notes">备注</h3>
+
+<p>注意,在使用递归调用时, 你不能使用此属性来重现出调用栈.请考虑以下代码:</p>
+
+<pre class="brush: js">function f(n) { g(n-1) }
+function g(n) { if(n&gt;0) f(n); else stop() }
+f(2)
+</pre>
+
+<p>当<code>stop()函数被调用时,调用栈是这样的</code>:</p>
+
+<pre class="brush: js">f(2) -&gt; g(1) -&gt; f(1) -&gt; g(0) -&gt; stop()
+</pre>
+
+<p>由于下面的表达式为 true(只保留函数最后一次被调用时的caller):</p>
+
+<pre class="brush: js">stop.caller === g &amp;&amp; f.caller === g &amp;&amp; g.caller === f
+</pre>
+
+<p>所以如果你尝试在<code>stop()</code>函数中获取调用栈的话:</p>
+
+<pre class="brush: js">var f = stop;
+var stack = "调用栈:";
+while (f) {
+ stack += "\n" + f.name;
+ f = f.caller;
+}
+</pre>
+
+<p>则上面的代码会进入一个死循环.</p>
+
+<p>有一个特殊属性 <code>__caller__</code>, 可以返回调用当前函数的函数的活动对象(可以用来重现出整个调用栈), 但由于安全原因的考虑,该属性已被删除.</p>
+
+<h2 id="Examples" name="Examples">例子</h2>
+
+<h3 id="Example:_Checking_the_value_of_a_function.27s_caller_property" name="Example:_Checking_the_value_of_a_function.27s_caller_property">例子: 检测一个函数的<code>caller</code>属性的值</h3>
+
+<p>下例用来得出一个函数是被谁调用的<code>.</code></p>
+
+<pre class="brush: js">function myFunc() {
+ if (myFunc.caller == null) {
+ return ("<span><span class="string">该函数在全局作用域内被调用</span></span>!");
+ } else
+ return ("调用我的是函数是" + myFunc.caller);
+}
+</pre>
+
+<h2 id="浏览器兼容性">浏览器兼容性</h2>
+
+<p>Function.caller目前被所有主流浏览器支持: Firefox, Safari, Chrome, Opera 和 IE. <a class="external" href="http://dl.dropbox.com/u/534786/callertest.html" title="http://dl.dropbox.com/u/534786/callertest.html"><span style="text-decoration: underline;">查看检测结果</span></a>.</p>