获取无效的形式参数

Question

这是一个SO挑战

我想知道有人如何在函数中获得无效的形式参数,而没有arguments对象模拟不知道参数解构赋值的格式.这不是ECMAScript问题,仅适用于JavaScript.

你mySolution无法访问arguments或test.您将获得一个args包含参数名称的数组.必须返回一个对象,该对象具有每个参数的属性,该参数是传递给函数的参数.总之,results[prop]必须=== test[prop].您的解决方案不应该依赖于错误或安全漏洞,因为它们将来可能不存在.我想到的这个问题的解决方案不依赖于任何错误.

(function () {
    function mySolution ({
        var,
        this,
        function,
        if,
        return,
        true
    }) {
        // prohbit reference to arguments and the test object
        var test = arguments = null,

        args = ['var', 'this', 'function', 'if', 'return', 'true'],
        results = {};

        // put your solution here

        return results;
    };
    var test = {
        "var"     : {},
        "this"    : {},
        "function": {},
        "if"      : {},
        "return"  : {},
        "true"    : {}
    },
    results = mySolution(test),
    pass = true;

    for (var prop in test)
        if (test.hasOwnProperty(prop))
            if (results[prop] !== test[prop])
                pass = false;

    alert(pass ? "PASS" : "FAIL")
}());

这是我接受的两种可能的解决方案之一:

(function () {
    function mySolution ({
        var,
        this,
        function,
        if,
        return,
        true
    }) {
        // prohbit reference to arguments and the test object
        var test = arguments = null,

        args = ['var', 'this', 'function', 'if', 'return', 'true'],
        results = {};

        var i = args.length;
        while (i--) {
            results[args[i]] = eval("function::" + args[i]);
            // function::[args[i]] won't work unless you eval() it
        }

        return results;
    };
    var test = {
        "var"     : {},
        "this"    : {},
        "function": {},
        "if"      : {},
        "return"  : {},
        "true"    : {}
    },
    results = mySolution(test),
    pass = true;

    for (var prop in test)
        if (test.hasOwnProperty(prop))
            if (results[prop] !== test[prop])
                pass = false;

    alert(pass ? "PASS" : "FAIL")
}());

该解决方案通过将默认function::命名空间与eval()范围结合使用来工作.

例如:foo.function::bar和foo.function::['bar']是一样的foo.bar.

Answer 1

100分

(function () {
    function mySolution ({
        var,
        this,
        function,
        if,
        return,
        true
    }) {
        // prohbit reference to arguments and the test object
        var test = arguments = null,

        args = ['var', 'this', 'function', 'if', 'return', 'true'],
        results = {};

        // put your solution here
        var getEscUnicode = function(str) {
            var ret = "";
            for(var j = 0; j < str.length; j++) {
                var temp = parseInt(str.charCodeAt(j)).toString(16).toUpperCase();
                for(var i=0; i < 5 - temp.length; i++) {
                    temp = "0" + temp;
                }
                ret = ret + "\\u" + temp;
            }
            return ret;

        }
        for(var i = 0; i < args.length; i++) {
            results[args[i]] = eval(getEscUnicode(args[i]));
        }
        return results;
    };
    var test = {
        "var"     : {},
        "this"    : {},
        "function": {},
        "if"      : {},
        "return"  : {},
        "true"    : {}
    },
    results = mySolution(test),
    pass = true;

    for (var prop in test)
        if (test.hasOwnProperty(prop))
                if (results[prop] !== test[prop])
                        pass = false;

    alert(pass ? "PASS" : "FAIL")
}());