JavaScript笔记_1

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1.JS中的数组：

1.1. Array literal

<span style="font-size:14px;"><span style="font-size:14px;">var colors;colors=[ 'white',          'black',          'red' ];var el=document.getElementById('colors');el.textContent=colors[0];</span></span>

1.2. Array object

<span style="font-size:14px;"><span style="font-size:14px;">var colors=new Array('white',                     'black',                     'red' );var el=document.getElementById('colors');el.innerHTML=colors.item(0);</span></span>

2.JS中的对象

2.1 Object literal

<span style="font-size:14px;">var hotel = {};hotel.name = 'Park';hotel.rooms = 120;hotel.booked = 77;hotel.checkAvailability = function() {  return this.rooms - this.booked;  };</span>

2.2 Object Constructor

<span style="font-size:14px;">var hotel = new Object();hotel.name = 'Park';hotel.rooms = 120;hotel.booked = 77;hotel.checkAvailability = function() {  return this.rooms - this.booked;  };</span>

2.3 Object literal 2(创建带有属性和方法的对象)

<span style="font-size:14px;">var hotel = {  name : 'Park',  rooms : 120,  booked : 77,  checkAvailability : function() {    return this.rooms - this.booked; // Need "this" because inside function  }};</span>

2.4 Object Constructor 2

<span style="font-size:14px;">// Create the template for objects that are hotelsfunction Hotel(name, rooms, booked) {  this.name = name;  this.rooms = rooms;  this.booked = booked;  this.checkAvailability = function() {    return this.rooms - this.booked;  };}// Create two hotel objectsvar quayHotel = new Hotel('Quay', 40, 25);var parkHotel = new Hotel('Park', 120, 77);</span>

3.IIFE(immediately invoked function expression)

var area=(function(){   var width=3;   var height=5;   return width*height;}());

最外面的括号确保解释器将之作为表达式。大括号后的一对小括号告诉解释器立即调用此函数。

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