和前面看到的一个面经是一模一样的,后悔没有仔细看,全是代码题
面试时间:4 月 1 日 移动终端部
1. 下面这些题目输出是什么?
1.1
```
(function(){
return typeof arguments;
})();
```
1.2
```
var foo = {
bar: function() { return this.baz; },
baz: 1
};
(function(){
return typeof arguments[0]();
})(foo.bar);
```
1.3
```
console.log([] == ![])
console.log( Function instanceof Object );
console.log( Object instanceof Function );
console.log( (function f(){}).__proto__ === Function.prototype);
```
1.4
```
function f(){ return f; }
consolelog(new f() instanceof f);
```
1.5
```
function foo(){
this.a = 100;
this.b = 200;
}
function goo(){
this.c = 300;
this.d = 400;
}
var seed = new foo(); //1
foo.prototype.fuss = function(fn) {
fn.prototype = seed;
seed = new fn; //2
return this; //3
}
var a = seed.fuss(goo);
console.log(a.c);
console.log(a === seed );
console.log(seed.a);
```
1.6
```
function foo(){
this.a = 100;
this.b = 200;
}
function goo(){
this.c = 300;
this.d = 400;
}
var seed = new foo(); //1
foo.prototype.fuss2 = function(fn) {
fn.prototype = seed;
return new fn;
}
var a = seed.fuss2(goo);
if ( "fuss2" in a ) {
var b = a.fuss2(foo);
}
console.log(Object.prototype.hasOwnProperty.call(a, "a"));
console.log("b" in a);
console.log("fuss2" in a);
console.log("c" in b);
```
1.7
```
const parent = function() {
const result = [];
const child = () => {
for (let num of arguments) {
result.push(num);
}
return result;
}
return child(1, 2, 3);
}
const result = parent(4, 5, 6, 7);
console.log(JSON.stringify(result));
```
1.8
```
var target = function() { return "I am the target"; };
var handler = {
apply: function(receiver, ...args) {
return "I am the proxy";
}
};
var p = new Proxy(target, handler);
console.log(p() === "I am the proxy");
1.1
```
(function(){
return typeof arguments;
})();
```
1.2
```
var foo = {
bar: function() { return this.baz; },
baz: 1
};
(function(){
return typeof arguments[0]();
})(foo.bar);
```
1.3
```
console.log([] == ![])
console.log( Function instanceof Object );
console.log( Object instanceof Function );
console.log( (function f(){}).__proto__ === Function.prototype);
```
1.4
```
function f(){ return f; }
consolelog(new f() instanceof f);
```
1.5
```
function foo(){
this.a = 100;
this.b = 200;
}
function goo(){
this.c = 300;
this.d = 400;
}
var seed = new foo(); //1
foo.prototype.fuss = function(fn) {
fn.prototype = seed;
seed = new fn; //2
return this; //3
}
var a = seed.fuss(goo);
console.log(a.c);
console.log(a === seed );
console.log(seed.a);
```
1.6
```
function foo(){
this.a = 100;
this.b = 200;
}
function goo(){
this.c = 300;
this.d = 400;
}
var seed = new foo(); //1
foo.prototype.fuss2 = function(fn) {
fn.prototype = seed;
return new fn;
}
var a = seed.fuss2(goo);
if ( "fuss2" in a ) {
var b = a.fuss2(foo);
}
console.log(Object.prototype.hasOwnProperty.call(a, "a"));
console.log("b" in a);
console.log("fuss2" in a);
console.log("c" in b);
```
1.7
```
const parent = function() {
const result = [];
const child = () => {
for (let num of arguments) {
result.push(num);
}
return result;
}
return child(1, 2, 3);
}
const result = parent(4, 5, 6, 7);
console.log(JSON.stringify(result));
```
1.8
```
var target = function() { return "I am the target"; };
var handler = {
apply: function(receiver, ...args) {
return "I am the proxy";
}
};
var p = new Proxy(target, handler);
console.log(p() === "I am the proxy");
2 . 实现一个Promise.all函数
Promise.all = function(arr) {
};
3. 给定后序遍历和中序遍历顺序构造二叉树
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