JavaScript:遍历原型链,调用栈,作用域链

function getPrototypeChain(obj) {
    var protoChain = [];
    while (obj = Object.getPrototypeOf(obj)) {
        protoChain.push(obj);
    }
    protoChain.push(null);
    return protoChain;
}

>getPrototypeChain(new String(""))
[String, Object, null]                     //依次是String.prototype,Object.prototype,null
  
>getPrototypeChain(function(){})
[function Empty() {}, Object, null]        //依次是Function.prototype,Object.prototype,null

function getCallStack() {
    var stack = [];
    var fun = getCallStack;
    while (fun = fun.caller) {
        stack.push(fun)
    }
    return stack
}

function a() {
    b()
}

function b() {
    c()
}

function c() {
    alert(getCallStack().map(function (fun) {
        return fun.name  //使用了非标准的name属性
    }))  
}

a()  //弹出c,b,a

b()  //弹出c,b

> (function(i){try{(function m(){++i&&m()}())}catch(e){return i}})(0)
50761

function getScopeChain(fun) {
    var scopeChain = [];
    while (fun = fun.__parent__) {
        scopeChain.push(fun);
    }
    return scopeChain;
}

var a = 0;
(function fun1() {
    var a = 1;
    (function fun2() {
        var a = 2;
        (function fun3() {
            var a = 3;
            getScopeChain(function () {}).map(function (obj) {
                print("-----------------------------")
                for(var i in obj){
                    print(i + ":" + (obj[i].name?obj[i].name:obj[i]))
                }
            })
        })()
    })()
})()

-----------------------------           //函数fun3
arguments:[object Arguments]        
a:3
fun3:fun3
-----------------------------           //函数fun2
arguments:[object Arguments]
a:2
fun2:fun2
-----------------------------           //函数fun1
arguments:[object Arguments]
a:1
fun1:fun1
-----------------------------           //全局上下文
a:0
getScopeChain:getScopeChain