Detailed explanation of the array structure in JavaScript programming, javascript Array

Detailed explanation of the array structure in JavaScript programming, javascript Array

An array object uses a separate variable name to store a series of values.
Create an array and assign values to it:
Instance

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

What is an array?
An array object uses a separate variable name to store a series of values.
If you have a group of data (for example, car name), there are independent variables as follows:

var car1="Saab";var car2="Volvo";var car3="BMW";

However, if you want to find a car? What about 300 instead of 3 vehicles? This is not an easy task!
The best way is to use arrays.
An array can store all values with a variable name, and can access any value with the variable name.
Each element in the array has its own ID so that it can be easily accessed.
Create an array
There are three methods to create an array.
The following code defines an array object named myCars:
1: conventional method:

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

2: simple mode:

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

3: literal:

var myCars=["Saab","Volvo","BMW"];

Access Array
By specifying the array name and index number, you can access a specific element.
The following instance can access the first value of the myCars array:

var name=myCars[0];

The following example modifies the first element of the array myCars:

myCars[0]="Opel";

Lamp [0] is the first element of the array. [1] is the second element of the array.

You can have different objects in an array.
All JavaScript variables are objects. An array element is an object. A function is an object.
Therefore, you can have different variable types in the array.
You can include object elements, functions, and arrays in an array:

myArray[0]=Date.now;myArray[1]=myFunction;myArray[2]=myCars;

Array methods and attributes
Use the predefined attributes and methods of the array object:

var x=myCars.length       // the number of elements in myCarsvar y=myCars.indexOf("Volvo")  // the index position of "Volvo"

Create a New Method
The prototype is a JavaScript global constructor. It can build the attributes and methods of New Javascript objects.
Instance: Create a new method.

Array.prototype.ucase=function(){ for (i=0;i<this.length;i++) {this[i]=this[i].toUpperCase();}}

In the preceding example, a new array method is created to convert lowercase characters of an array into uppercase characters.