javascript中的数组、Map、Set和Iterator
javascript中的数组、Map、Set和Iterator
数组
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script>
"use strict"
var age = [1,2,3,4,56,5,12,45];
age.forEach(function (value){
console.log(value);
})
console.log("=======================");
// var var index in object
for(var num in age){
if(age.hasOwnProperty(num)){
console.log("存在");
}
console.log(age[num]);
}
</script>
</head>
<body>
</body>
</html>
Map
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script>
"use strict"
//Es6新特性 Map和Set
//学生的名字 成绩
var map = new Map([['zhangsan',22],['lisi',80],['wangwu',70],['zjaoliu',40]]);
var name = map.get("zhangsan");
console.log(name);
map.set('admin',75);//新增
console.log(map.get("admin"));
map.delete("zhangsan");//删除
console.log(map);
</script>
</head>
<body>
</body>
</html>
Set
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script>
"use strict"
var set = new Set([3,34,22,22,22]);
console.log(set);
set.add(23);
console.log(set);
set.add(34);//添加
console.log(set);
set.delete(3);//删除
console.log(set);
console.log(set.has(34));//是否包含某个元素
</script>
</head>
<body>
</body>
</html>
Iterator
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script>
"use strict"
//es6新特性
var a = [1,2,3,4];
for (let x of a){
console.log(x);
}
console.log("=========================");
var map = new Map([['zhangsan',1],['lisi',2],['wangwu',3]]);
for (let x of map){
console.log(x);
}
console.log("=========================");
var set = new Set([1,2,3]);
for (let x of set){
console.log(x);
}
</script>
</head>
<body>
</body>
</html>