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You can loop any Array by using different types of looping statements in JavaScript, which I have previously posted. In this post you can loop through JavaScript Array. At first let you know basic concepts of Array ie. defining array, adding values to the array and accessing array elements. 

The Array object is used to store a set of values in a single variable name. You can define Array object with the new keyword.

The following line of code defines an Array object called  myArray.

var myArray=new Array()

You can also define the array size by passing an integer argument as follows.

var myArray=new Array(5)

You can add the values to an array as the following.

var myArray=new Array()
myArray[0]="value1"
myArray[1]="value2"
myArray[2]="value3"


You can also give values to the arrays while defining it as below.

var myArray=new Array("value1", "value2", "value3")

While accessing Arrays, you can refer to a particular element in an array by referring to the name of the array and the index number. The index number starts at 0. The following line accesses the first value of the array myArray.

document.write(myArray[0])

Loop Through JavaScript Array

You can loop any Array by using any of the following looping statements in JavaScript.

Using For loop

You can loop any Array by using For Loop as below.

var myArray=new Array()
myArray[0]="value1"
myArray[1]="value2"
myArray[2]="value3"

for(i=0; i<myArray.length;i++)
{
document.write(myArray[i])
}

Example:

<html>
<head></head>
<body>
<script type="text/javascript">
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/>")
}
</script>

Using For .... In Statement

You can loop any Array by using For .... In Statement as below.

var myArray=new Array()
myArray[0]="value1"
myArray[1]="value2"
myArray[2]="value3"

for(x in myArray)
{
document.write(myArray[x])
}

Example:

<html>
<head></head>
<body>
<script type="text/javascript">
var mycars=new Array()
mycars[0]="Saab"
mycars[1]="Volvo"
mycars[2]="BMW"

for(x in mycars)
{
document.write(mycars[x]+"<br/>")
}
</script>
</body>
</html>

Preview:

You can also loop any Array by using other looping statements like while and Do ... while loops as the same methods given above.

Read Next:How to Concatenate, Join and Sort Array in JavaScript?

Related Search Terms

• Javascript For Loop Through Array

• Javascript Array For .. In Statement

• JavaScript Array Loop

Loops in JavaScript are used to execute the same block of code a specified number of times or while a specified condition is true.

In JavaScript there are two different kinds of loops which are for loop, which loops through a block of code a specified number of times and while loop, which loops through a block of code while a specified condition is true.

JavaScript For Loop

The for loop is used when you know in advance how many times the script should run.

Syntax:

for(var=startvalue; var<=endvalue;var=var+increment)
{
code to be executed
}

Example:

<html>
<head>
</head>
<body>
<script type="text/javascript">
var i=0
for (i=0;i<=10;i++){

document.write("The number is" +i)
document.write("<br/>")}
</script>
</body>
</html>

The above example defines a loop that starts with i=0. The loop will continue to run as long as i is less than, or equal to 10. i will increase by 1 each time the loop runs.

Preview:

JavaScript While Loop

The while loop is ued when you want the loop to execute and continue executing while the specified condition is true.

Syntax:

while (var<=endvalue)
{
code to be executed
}

Example:

<html>
<head></head>
<body>
<script type="text/javascript">
var i=0
while(i<=10)
{
document.write("The number is "+i)
document.write("<br/>")
i=i+1
}
</script>
</body>
</html>

The example above defines a loop that starts with i=0. The loop will continue to run as long as i is less than, or equal to 10. i will increase by 1 each time the loop runs.

Preview:

JavaScript do .... while Loop:

The do .... while loop is a variant of the while loop. This loop will always execute a block of code Once, and then it will repeat the loop as long as the specified condition is true. The lop alway be executed at least once, even if the condition is false, because the code is executed before the condition is tested.

Syntax:

do
{
code to be executed
}
while (var<=endvalue)

Example:

<html>
<head></head>
<body>
<script type="text/Javascript">
var i=0
do
{
document.write("The number is "+i)
document.write("<br/>")
i=i+i
}
while (i<0)
</script>
</body>
</html>

Preview:

JavaScrpt Break and Continue Statements

There are two special statements that can be used inside loops: break and continue.

Break

The break command will break the loop and continue executing the code that follows after the loop.

Example:

<html>
<head></head>
<body>
<script type="text/javascript">
var i=0
for(i=0;i<=10;i++)
{
if (i==3) {break}
document.write("The number is " +i)
document.write("<br/>")
}
</script>
</body>
</html>

Preview:

Continue

The continue command will break the current loop and continue with the next value.

Example:

<html>
<head></head>
<body>
<script type="text/javascript">
var i=0
for(i=0;i<=10;i++)
{
if (i==3) {continue}
document.write("The number is " +i)
document.write("<br/>")
}
</script>
</body>
</html>

Preview:

Read Next:How to Loop Through JavaScript Array?

Related Search Terms

• Javascript For Loop

• Javascript Do While Loop

• JavaScript While Loop

• JavaScript Break and Continue