3 different styles to define Array in JavaScript

Sourav.Kayal
Posted by in JavaScript category on for Beginner level | Points: 250 | Views : 2021 red flag
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Various styles to declare array in JavaScript

3 different styles to define Array in JavaScript

In this article we will learn the concept of array in JavaScript. If you have programming background then you already knows the concept of Array in various programming language. The fundamental idea behind array is to collect similar element together.

If we can do so, then the collection can be access by it’s index. There are various ways to implement array in JavaScript. In this article we will learn them one by one.

First Style to define array

This is one style to represent array. We can keep the entire similar element within [] bracket. Try to understand the below code.

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="JavaScript.aspx.cs" Inherits="JavaScript.JavaScript" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
</head>
<body>
    <form id="form1" runat="server">
        <script>
            var arr = ['a','b','c'];
            alert(arr[0]);
        </script>
    </form>
</body>
</html>

The implementation is very simple, only we have defined array using “var” keyword. Then we are accessing the 0th element of the array. Here is output.


Second style to define array

This is another style to define array. Here we will use Array() function to create array. Have a look on below code.

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="JavaScript.aspx.cs" Inherits="JavaScript.JavaScript" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
</head>
<body>
    <form id="form1" runat="server">
        <script>
            var arr = new Array("One", "Two", "Three");
            alert(arr[0]);
        </script>
    </form>
</body>
</html>

The new operator will create a collection of string into “arr” which we have declared as array. Then we are accessing the 0th element of Array. Here is sample output.


Third style to define array

This style is little similar to second style , only the difference is that we are not creating element in time of Array() creation. Here is sample example.

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="JavaScript.aspx.cs" Inherits="JavaScript.JavaScript" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
</head>
<body>
    <form id="form1" runat="server">
        <script>
            var arr = new Array();
            arr[0] = 100;
            arr[1] = "Sourav";
            arr[2] = "Kayal";
 
            alert(arr[1] + arr[2]);
        </script>
    </form>
</body>
</html>

The nice face to observe , in JavaScript array is type less. As we know JavaScript is loosely type checking language, it means there is no different data type (like int,char,string) in Javascript. So that Array() also works in same fashion. We can set any data type in one array. At first line of initialization we are setting int(number in JavaScript) and then we are setting string into it.

We are trying to access the 1st and 2nd value from array. Here is output.


 Conclusion:-

In this small article we have learned three different styles to define array. Hope you have understood all the concepts.  Array also contains many properties, in coming article we will understand it.


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About the Author

Sourav.Kayal
Full Name: Sourav Kayal
Member Level: Silver
Member Status: Member,MVP
Member Since: 6/20/2013 2:09:01 AM
Country: India
Read my blog here http://ctrlcvprogrammer.blogspot.in/
http://www.dotnetfunda.com
I am .NET developer working for HelixDNA Technologies,Bangalore in healthcare domain. Like to learn new technology and programming language. Currently working in ASP.NET ,C# and other microsoft technologies.

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