<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
</body>
<script>
var arr=new Array(1)
var arr1=new Array(2)
var arr2=new Array(1,2)
var arr5=new Array('abc')
var arr6=new Array([0]) //单个非数值。比如字符串，布尔值，对象
var arr7=new Array(0) //单个非数值。比如字符串，布尔值，对象
var arr8=new Array(true) //单个非数值。比如字符串，布尔值，对象
var arr3=new Array(3.2)
var arr4=new Array(-3)
console.log(arr3.length); //invalid array length
console.log(arr4.length); //invalid array length
console.log(arr5); //[abc]
console.log(arr6); //[Array[1]]
console.log(arr7); //[]
console.log(arr8); //[true]
console.log(arr.length);// 1
console.log(arr); //[empty]
console.log(arr1.length);// 2
console.log(arr1); //[empty*2]
console.log(arr2.length);// 2
console.log(arr2); //[1,2]
</script>
</html>
// bad
var arr = new Array(1, 2);
// good
var arr = [1, 2];