ES object 扩展
ES object 扩展1.
<!DOCTYPE html> <html> <head> <link rel="shortcut icon" href="./assets/favicon.ico" /> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0"> <title>webpack</title> </head> <body> <script type="text/javascript"> // ******object 扩展************
//1. var obj={name:'kebo', sex:'男'} var obj1 =Object.create(obj,{ age:{ value:25, writable:true,//可被修改 configurable:true, //可被删除 enumerable:true } }) console.log("obj1-----",obj1) obj1='kebo' // 修改对象的属性 // console.log("obj1-----###",obj1) // delete obj1 // 删除对象 // console.log(obj1) for (var i in obj1){ console.log(i) }
</script>
</body>
</html>
ES object 扩展2.
<!DOCTYPE html>
<html>
<head>
<link rel="shortcut icon" href="./assets/favicon.ico" />
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<title>webpack</title>
</head>
<body>
<script type="text/javascript">
// ******object 扩展************
var obj2 ={fistName:'kebe',lastName:'bryant'};
Object.defineProperties(obj2,{
fullName: {
get: function(){ // 获取对应的值 惰性求值 被调用时才执行
return this.fistName + ' ' + this.lastName;
},
set: function(data){ // 监听对象的属性 发送改变是调用
console.log("obj2-------------",data)
var names=data.split(' ')
this.fistName=names[0]
this.lastName=names[1]
return this.fistName + ' ' + this.lastName;
}
},
})
console.log(obj2)
console.log('before',obj2.fullName)
obj2.fullName='kebe kebe';
console.log('after',obj2.fullName)
</script>
</body>
</html>
ES object 扩展3
<!DOCTYPE html>
<html>
<head>
<link rel="shortcut icon" href="./assets/favicon.ico" />
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<title>webpack</title>
</head>
<body>
<script type="text/javascript">
// ******object 扩展************
var obj3 ={
fistName:'kebe',
lastName:'bryant',
get function(){ // 获取对应的值 惰性求值 被调用时才执行
return this.fistName + ' ' + this.lastName;
},
set function(data){ // 监听对象的属性 发送改变是调用
console.log("obj2-------------",data)
var names=data.split(' ')
this.fistName=names[0]
this.lastName=names[1]
return this.fistName + ' ' + this.lastName;
}
}
console.log(obj2)
console.log('before',obj2.fullName)
obj2.fullName='kebe kebe';
console.log('after',obj2.fullName)
</script>
</body>
</html>
ES Arrary map, forEach ,filter(返回条件为true 的值)
var arr=[1,5,9,4,465,485,56,25,4,48,54]
console.log('4的下标',arr.indexOf(4))
console.log('4的下标',arr.lastIndexOf(4))
arr.forEach(function(item,index){
console.log("item--",item)
})
var arr1=arr.map((item,index)=>{
return item+10;
})
console.log("arr1--",arr1)
var arr2=arr.filter((item,index)=>{
return item >25;
})
console.log("arr2 大于25的数--",arr2)
ES 函数语法 this指向绑定
var obj1={userName:'kobe'}
function foo1(data) {
console.log(this,data)
}
foo.call(obj1,33) //直接从第二个数据开始穿入
foo.apply(obj1,[33,45]) //第二个参数必须是数组
var bar = foo.bind(obj) //绑定后没有以及执行 返回一个值
console.log('bar',bar)
bar()
console.log('2222222222')
foo.bind(obj)(33666) //加（）调用函数 直接从第二个数据开始穿入
var obj1={userName:'kobe'}
setTimeout(function () {
console.log("this---",this)
}.bind(obj1),1000)