微信重大更新：一對一聊天為外部連結和電商連結“放行”
阿新 • • 發佈：2021-11-29
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
</body>
</html>
<script>
var arr1=[1,2,3,4]
var arr2=['a','b','c',3214,351,{name:'xiaoming'
,age:12,hobbies:['英雄聯盟','王者榮耀']}
,[1,2,3]]
var arr3 = new Array(9,3,0)
console.log(arr3)
var arr4 = []//推薦這樣使用更簡單
console.log(arr2.length)
console.log(arr3.length)
arr2[2]='d'
console.log(arr2)
arr3=[11]='arr3d'
console.log(arr3)
console.log(arr1)
arr1.push('d')
console.log(arr1)
arr1.pop()//從最後刪除
console.log(arr1)
arr1.shift()//從前面刪除
console.log(arr1)
arr1.unshift(0)//從前面增加
console.log(arr1)
console.splice(1,0,'a','b')
console.log(arr1)//任何位置增加刪除
//typeof
var a=1 ,b='1' , c=true,d=null
console.log(typeof a) //語法糖
console.log((e.length))
if(typeof e=="object"&&(e.length||e.length==0)){
console.log('e is Array')
}
console.log(Array.isArray(e))
//if (Array.isArray(e)){
//console.log('是陣列')
//}else{
// console.log('不是陣列')
//}
</script>