How to Concatenate, Join and Sort an Array in JavaScript?

In the previous post, I have already published the article “How to Loop Through JavaScript Array“. This article tells the ways to loop any Array by using different types of looping statements in JavaScript. Along with accessing an element of an array using looping statements, you can also concatenate, join and sort an array in JavaScript.

In this post, you will learn in-depth about concatenating, Joining and Sort ing an array in JavaScript.

How to Join Two Arrays using Concat()

Using concat() method, you can join to arrays array1 and array2 as below.

<script>
var array1=new Array(3);
array1[0]="Saab"
array1[1]="Volvo"
array1[2]="BMW"
var array2=new Array(3);
array2[0]="Yamaha"
array2[1]="Honda"
array2[2]="Bajaj"
var array3=array1.concat(array2);
for(i=0; i<array3.length;i++){
document.write(array3[i]+"<br/>")
}
</script>

Preview:

Here the method array1.concat(array2) concentrates two arrays “array1” and “array2” and displays the concatenated array named “array3”.

Read Also: How to Write Conditional Statements in JavaScript?

How to Put Array Elements Into a String using Join()

You can use the join() method to put all the elements of an array into a string like the following script.

<script>
var array1=new Array(3);
array1[0]="Yamaha"
array1[1]="Honda"
array1[2]="Bajaj"
document.write(array1.join()+"<br/>");
document.write (array1.join("."));
</script>

Preview:

Here the method array1.join() joins the items of arrays with “,” and array1.join(“.”) joins the items of arrays with “.” and displays them.

Read Also: How to Show Pop Up Boxes Using JavaScript?

How to Sort String Array using sort()

Using the sort() method, you can sort the elements of the string array as given below.

<script>
var array1=new Array(6);
array1[0]="Saab"
array1[1]="Volvo"
array1[2]="BMW"
array1[3]="Yamaha"
array1[4]="Honda"
array1[5]="Bajaj"
document.write(array1+"<br/>");
document.write (array1.sort());
</script>

Preview:

Here the method array1.sort() sorts the items of arrays on alphabetical ascending order and displays them joining with comma.

Read Also: How to Loop using JavaScript?

How to Sort Numeric Array using sort()

Using the sort() method, you can sort the elements of the numeric array as given below.

<script>
var array2=new Array(6);
array2[0]=10
array2[1]=5
array2[2]=40
array2[3]=25
array2[4]=35
array2[5]=95
function sortNumber(a,b) {return a - b;}
document.write(array2+"<br/>");
document.write (array2.sort(sortNumber));
</script>

Preview:

Here the method array2.sort(sortNumber) sorts the items of arrays on numerical ascending order and displays them joining with comma.

Since there are concatenate, join and sort methods to an array in order to manipulate the items in JavaScript. There are also other more methods for manipulating array elements, which are listed below along with their description. You can use them as the methods given above.

• pop(): Removes and returns the last element of an array
• push(): Adds one or more elements to the end of an array and returns the new length.
• reverse(): Reverses the order of the elements in an array
• toString(): Converts an array to string and returns the result.

Read Next: How to use Round, Random, Min, and Max in JavaSript