找出Closure是否提供方法（JavaScript模块模式）

Question

鉴于以下代码，有没有办法让我检测通过调用fn（）返回的闭包是否包含给定的方法而不必执行fn本身？

// Example function which provides a closure with an 'execute' method.
var fn = function () {
    return {
        execute: function () {
        }
    }; 
};


// Test for the presense of an 'execute' method in the function's closure
if ("function" === typeof fn().execute) {
    print("supplied function includes an execute method");
} else {
    print("supplied function does not include an execute method");
}

谢谢！

Answer 1

不，没有。没有它就无法检查返回值。 - Felix Kling