让人蛋疼的JavaScript语法特性

在知乎上看到的有人发布的和javascript有关的试题，和大家分享下，虽然是N久前的事了，但这些题相当经典，不免让人觉得javascript真是门蛋疼的语言。

1.

  (function () { 

        return typeof arguments; 

    })();

    A. "object"

    B. "array"

    C. "arguments"

    D. "undefined"

答案：A

2.

var f = function g() {

                return 23;

            };

        typeof g();

        A. "number"

        B. "undefined"

        C. "function"

        D. Eorror

答案：D

3.

(function (x) {

            delete x;

            return x;

        })(1);

        A. 1

        B. null

        C. undefined

        D. Error

答案：A

4.

        var y = 1,

        x = y = typeof x;

        x;

        A. 1

        B. "number"

        C. undefined

        D. "undefined"

答案：D

5.

    (function f(f) {

            return typeof f();

        })(function () {

            return 1;

        });

        A. "number"

        B. "undefined"

        C. "function"

        D. Error

答案：A

6.

var foo = {

            bar: function () {

                return this.baz;

            },

            baz: 1

        };

        (function () {

            return typeof arguments[0]();

        })(foo.bar);

        A. "undefined"

        B. "object"

        C. "number"

        D. "function"

答案：A

7.

var foo = {

            bar: function () {

                return this.baz;

            },

            baz: 1

        };

        typeof (f = foo.bar)();

        A. "undefined"

        B. "object"

        C. "number"

        D. "function"

答案：A

8.

var f = (function f() {

            return "1";

        }, function g() {

            return 2;

        })();

        typeof f;

        A. "string"

        B. "number"

        C. "function"

        D. "undefined"

答案：B

9.

 var x = 1;

 if (function f() {}) {

 x += typeof f;

 }

 x;

 A. 1

 B. "1function"

 C. "1undefined"

 D. NaN

答案：C

10.

var x = [typeof x, typeof y][1];

        typeof typeof x;

        A. "number"

        B. "string"

        C. "undefined"

        D. "object"

答案：B

11.

(function (foo) {

            return typeof foo.bar;

        })({

            foo: {

                bar: 1

            }

        });

        A、“undefined”

        B、“object”

        C、“number”

        D、Error

答案：A

12.

(function f() {

            function f() {

                return 1;

            }

            return f();

            function f() {

                return 2;

            }

        })();

        A、1

        B、2

        C、Error (e.g. “Too much recursion”)

        D、undefined

答案：B

13.

 function f() {

        return f;

    }

    new f() instanceof f;

    A、true

    B、false

答案：B

14.

with (function(x, undefined){}) length;

        A、1

        B、2

        C、undefined

        D、Error

答案：B

15.

以下哪条语句会产生运行错误:（）          

A.var obj = ();           

B.var obj = [];        

C.var obj = {};        

D.var obj = //; 

答案：A