JavaScript 好题汇总分享（持续更新，看到好题就写）

向右看齐 2023-03-01 11:51 32阅读 0赞

## 前言 ##

本文搜集的题目，均来自各大网课、面试题等

## 预编译相关 ##

### 1 ###

a = 100;
    function demo(e) {
        
    	function e() {
          }
    	arguments[0] = 2;
    	console.log(e);
    	if(a){
        
    		var b = 123;
    		function c() {
        
    		}
    	}
    	var c;
    	a = 10;
    	var a;
    	console.log(b);
    	f = 123;
    	console.log(c);
    	console.log(a);
    }
    var a;
    demo(1);
    console.log(a);
    console.log(f);

### 2 ###

function bar(){
        
    	return foo;
    	foo = 100;
    	function foo() {
        }
    	var foo = 111;
    }
    console.log(bar());

console.log(bar());
    function bar() {
        
    	foo = 10;
    	function foo() {
        }
    	var foo = 11;
    	return foo;
    }

## 类型转化相关 ##

if (typeof (a) && -true + (-undefined) + "") {
        
    		document.write("基础扎实");
    }
    if(11 + "11" * 2 == 33){
        
    	document.write("基础扎实");
    }
    !!" " + !!"" - !!false || document.write('你觉得能打印，你就是猪');

## 闭包 ##

## 原型 ##

Person.prototype.name = 'Jack';
    function Person() {
        
    
    }
    person = new Person();
    Person.prototype.name = 'Cherry';
    console.log(person.name);

Person.prototype.name = 'Jack';
    function Person() {
        
    
    }
    person = new Person();
    Person.prototype = {
        
    	name: 'Cherry'
    }
    console.log(person.name);

function Person() {
        
    
    }
    Person.prototype.name = 'Jack';
    Person.prototype = {
        
    	name: 'Cherry'
    }
    person = new Person();
    console.log(person.name);

## this ##

var foo = '123';
    
    function f() {
        
    	this.foo = '234';
    	console.log(foo);
    }
    new f();

## 数组 ##

function addTolist(item, list) {
        
    	return list.push(item);
    }
    var result = addTolist('apple', ['banana']);
    console.log(result);

//类数组
    var obj = {
        
    	'2': 'a',
    	'3': 'b',
    	'length': 2,
    	'push': Array.prototype.push
    }
    obj.push('c');
    obj.push('d');
    console.log(obj);

## 暂时未知类型 ##

(window.x || (window.x = "bar")); 
    console.log(window.x);

function a() {
        
    	console.log('a');
    }();          //报错
    function a(a, b, c, d) {
        
    		console.log(a + b + c + d);
    }(1, 2, 3, 4);//不报错，但是不执行

var x = 1;
    if (function a() {
        }) {
        
    	x += typeof (a);
    }
    console.log(x);