JavaScript learning - Array object

Defining arrays

Array objects are used to store a series of values in separate variable names.
We use the keyword new to create array objects. The following code defines an array object called myArray:

var myArray=new Array()；

There are two ways to assign values to an array (you can add as many values as you want, just as you can define as many variables as you want).
1,

var mycars=new Array() mycars[0]="Saab" mycars[1]="Volvo" mycars[2]="BMW"

You can also use an integer argument to control the size of the array:
var mycars=new Array(3)
mycars[0]="Saab"
mycars[1]="Volvo"
mycars[2]="BMW"

2,

var mycars=new Array("Saab","Volvo","BMW")；

Note: if you need to specify a numeric or logical value in an array, the variable type should be a numeric or boolean variable, not a character variable.

Access array

By specifying the array name and index number, you can access a specific element.

document.write(mycars[0]) // Output: Saab

Modify the values in an existing array

To modify the values in an existing array, simply add a new value to the specified subscript number:

mycars[0]="Opel";

Now?

document.write(mycars[0]);// Output: Opel

Sample code

var mycars = new Array() mycars[0] = "Saab" mycars[1] = "Volvo" mycars[2] = "BMW" for (i=0;i<mycars.length;i++) { document.write(mycars[i] + "<br />") }

var x var mycars = new Array() mycars[0] = "Saab" mycars[1] = "Volvo" mycars[2] = "BMW" for (x in mycars) { document.write(mycars[x] + "<br />") }

var arr = new Array(3) arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" var arr2 = new Array(3) arr2[0] = "James" arr2[1] = "Adrew" arr2[2] = "Martin" document.write(arr.concat(arr2))

var arr = new Array(3); arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" document.write(arr.join()); document.write("<br />"); document.write(arr.join("."));

var arr = new Array(6) arr[0] = "George" arr[1] = "John" arr[2] = "Thomas" arr[3] = "James" arr[4] = "Adrew" arr[5] = "Martin" document.write(arr + "<br />") document.write(arr.sort())

function sortNumber(a, b) { return a - b } var arr = new Array(6) arr[0] = "10" arr[1] = "5" arr[2] = "40" arr[3] = "25" arr[4] = "1000" arr[5] = "1" document.write(arr + "<br />") document.write(arr.sort(sortNumber))

1 July 2020, 10:33 | Views: 4581