让人蛋疼的JavaScript语法特性_基础知识

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