JS array Detailed explanation of array

#Declaration method of array

//Create an array.

var arr1 = new Array();

arrayObj = new Array([size])

//Create an array and specify the length. Note that it is not the upper limit, but the length.

var a = new Array(5);

arrayObj = new Array([element0], [element1], ..., [elementN])

//Create an array and assign values.

var a = new Array(["b", 2, "a", 4,]);

arrayObj = [element0 , element1, ..., elementN]

//Abbreviation for creating an array and assigning values. Note that the square brackets here do not mean that they can be omitted.

var a = ["b", 2, "a", 4,];

Note: Pay attention to the " The difference between []” and without “[]”

var a = new Array(5); // refers to creating an array with a length of 5

var a = new Array([5]); // refers to creating an array with a length of 1, and the first digit is 5

Array operation (passing address)

##

var t2=new Array();
t2[0]=1;
t2[1]=2;
test2(t2); //传地址（数组）
function test2(var2) {
for(var i=0;i<var2.length;i++) {
var2[i]=var2[i]+1;
}
}
for(var i=0;i<t2.length;i++) {
alert(t2[i]); }