Array
The concept of array
一A collection of group numbers is called an "array".
var arr = [1,2,3,4,5];
var arr = ["Xiao Ming", "Male", 20, "Institute", "Anhui Province" , ];
Array elements
Each value in the array is called an "array element".
Array index
There are multiple values in the array, each value has a "number", passed "Number" can access each value in the array.
The "number" in the array is also called "subscript" or "index number".
The "subscript number" in the array is a positive integer starting from 0. That is to say: the index of the first array element is 0, the index of the second array element is 1, the index of the third array element is 2, and so on.
The subscript of the first array element must be 0, and the subscript of the last array element is: length-1.
The purpose of using an array is that it is convenient to use a loop to traverse the array.
##Access to array elements
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>php.cn</title>
<script>
var arr = ["涛哥" , "男" , 24, "大专" , "北京科技大学" ];
for(var i=0;i<5;i++){
document.write(arr[i]+"<br/>");
}
</script>
</head>
<body>
</body>
</html>The length of the array
