# JavaScript Program to Check Prime Number Example

Hello Friends,

Now let's see example of how to check prime number example. We will use how to check prime number in javascript. This is a short guide on check prime number. Let's get started with how to check prime number in javascript.

Here i will give you many example how you can check prime number javascript.

Example : 1
```<!DOCTYPE html>
<html>
<meta charset="utf-8">
<title>JavaScript Program to Check Prime Number Example - MyWebtuts.com</title>
<body>
<h2>JavaScript Program to Check Prime Number Example - MyWebtuts.com</h2>

<script type="text/javascript">
const num = parseInt(prompt("Enter a positive Number: "));
let isPrime = true;

if (num === 1) {
document.write("1 is neither Prime nor composite Number.");
}

else if (num > 1) {
for (let i = 2; i < num; i++) {
if (num % i == 0) {
isPrime = false;
break;
}
}

if (isPrime) {
document.write(`\${num} is a Prime Number`);
} else {
document.write(`\${num} is not a Prime Number`);
}
}

else {
document.write("The Number is not a Prime Number.");
}
</script>
</body>
</html>
```
Output : Example : 2
```<!DOCTYPE html>
<html>
<meta charset="utf-8">
<title>JavaScript Program to Check Prime Number Example - MyWebtuts.com</title>
<body>
<h3>JavaScript Program to Check Prime Number Example - MyWebtuts.com</h3>
<form name="myform">
Enter the number:
<input type="text" name=n value="">
<br><br>

<input type="button" value="Check" onClick="test()">
<br>
</form>
<script type="text/javascript">
function test() {
var n, i, flag = true;

n = document.myform.n.value;
n = parseInt(n)
for(i = 2; i <= n - 1; i++)
if (n % i == 0) {
flag = false;
break;
}
if (flag == true)
alert(n + " is Prime Number");
else
alert(n + " is not Prime Number");
}
</script>
</body>
</html>
```
Output :