What is an array ?
Something which belongs to the same type is ordered in series is called as array.
What is an array in Javascript ?
An array in javascript is an object that represents a group of same-typed elements.
Why is array used in Javascript ?
An array is used to store a collection of elements of the same type.
If we want to iterate a series number of similar elements, which can be achieved by storing elements in array.
How to construct an array in Javascript ?
There are three ways to construct array, some of them are listed below,
1. Array literal
2. Creating instance of Array directly
3. Using an Array constructor
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1. Array Literal
Example :
<!DOCTYPE html>
<html>
<head>
<title>Our title</title>
<script type="text/javascript">
var a = ["Abdul","87","Male","Tamilnadu"];
document.write("Name = "+a[0]+"<br/>");
document.write("Age = "+a[1]+"<br/>");
document.write("Sex = "+a[2]+"<br/>");
document.write("Location = "+a[3]+"<br/>");
</script>
</head>
<body></body>
</html>
Output :
Name = Abdul
Age = 87
Sex = Male
Location = Tamilnadu
2. Creating instance of Array directly
This can be done by using “new” keyword.
Example :
<!DOCTYPE html>
<html>
<head>
<title>Our title</title>
<script type="text/javascript">
var a = new Array();
a[0] = "Abdul";
a[1] = "Krishna";
a[2] = "Gandhi";
a[3] = "TamilNadu";
a[4] = "Butterfly";
a[5] = "Elephant";
a[6] = "Flower";
for(i=0;i<a.length;i++){
document.write("Array value of a of " + i + " = "+ a[i] + "<br/>");
}
</script>
</head>
<body></body>
</html>
Output :
Array value of a of 0 = Abdul
Array value of a of 1 = Krishna
Array value of a of 2 = Gandhi
Array value of a of 3 = TamilNadu
Array value of a of 4 = Butterfly
Array value of a of 5 = Elephant
Array value of a of 6 = Flower
3. Using an Array constructor
This is done using “new” keyword.
Example :
<!DOCTYPE html>
<html>
<head>
<title>Our title</title>
<script type="text/javascript">
var a = new Array("Abdul","Krishna","Gandhi","TamilNadu","Butterfly","Elephant","Flower");
for(i=0;i<a.length;i++){
document.write("Array value of a of " + i + " = "+ a[i] + "<br/>");
}
</script>
</head>
<body></body>
</html>
Output :
Array value of a of 0 = Abdul
Array value of a of 1 = Krishna
Array value of a of 2 = Gandhi
Array value of a of 3 = TamilNadu
Array value of a of 4 = Butterfly
Array value of a of 5 = Elephant
Array value of a of 6 = Flower
Javascript has a lot of array methods, some of them are listed below.
| Sno | Method | Description |
| 1 | concat() | This returns a new array object that contains two or more merged arrays. |
| 2 | copywithin() | This copies the part of the given array with its own elements and returns the modified array. |
| 3 | every() | This determines whether all the elements of an array are satisfying the provided function conditions. |
| 4 | fill() | This fills elements into an array with static values. |
| 5 | filter() | This returns the new array containing the elements that pass the provided function conditions. |
| 6 | find() | This returns the value of the first element in the given array that satisfies the specified condition. |
| 7 | findIndex() | This returns the index value of the first element in the given array that satisfies the specified condition. |
| 8 | forEach() | This invokes the provided function once for each element of an array. |
| 9 | includes() | This checks whether the given array contains the specified element. |
| 10 | indexOf() | This searches the specified element in the given array and returns the index of the first match. |
| 11 | join() | This joins the elements of an array as a string. |
| 12 | lastIndexOf() | This searches the specified element in the given array and returns the index of the last match. |
| 13 | map() | This calls the specified function for every array element and returns the new array |
| 14 | pop() | This removes and returns the last element of an array. |
| 15 | push() | This adds one or more elements to the end of an array. |
| 16 | reverse() | This reverses the elements of given array. |
| 17 | shift() | This removes and returns the first element of an array. |
| 18 | slice() | This returns a new array containing the copy of the part of the given array. |
| 19 | sort() | This returns the elements of the given array in a sorted order. |
| 20 | splice() | This add/remove elements to/from the given array. |
| 21 | unshift() | This adds one or more elements in the beginning of the given array. |