Question

基本上我喜欢具有instanceof Something === true的功能。

类似于MySpecialKindOfFunction，例如：

if (theFunction instanceof MySpecialKindOfFunction)

我尝试过设置 proto 和函数的构造函数而没有工作。

Answer 1

也许我不明白你的问题，但这是你想要达到的目标吗？

// Static class method.
Interface.ensureImplements = function(object) {
    if(arguments.length < 2) {
        throw new Error("Function Interface.ensureImplements called with " +
        arguments.length + " arguments, but expected at least 2.");
    }
    for(var i = 1, len = arguments.length; i < len; i++) {
        var interface = arguments[i];
        if(interface.constructor !== Interface) {
            throw new Error("Function Interface.ensureImplements expects arguments"
            + " two and above to be instances of Interface.");
        }
        for(var j = 0, methodsLen = interface.methods.length; j < methodsLen; j++) {
            var method = interface.methods[j];
            if(!object[method] || typeof object[method] !== 'function') {
                throw new Error("Function Interface.ensureImplements: object "
                + "does not implement the " + interface.name
                + " interface. Method " + method + " was not found.");
            }
        }
    }
};

我使用此代码来测试函数是否是一种接口。关键代码是：

if(interface.constructor !== Interface) {

要扩展课程，您可以这样做：

function Item () {

};

function Picture () {
    Item.call(this); // Call to superClass constructor with subclass instance
};


Picture.prototype = new Item();
Picture.prototype.constructor = Picture;

var picture = new Picture();
if(picture instanceof Item){ 
    alert("True");
} else {
    alert(false);
}

自定义“类”的功能

1 个答案: