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JavaScript code to check whether a Number is Prime or Not

JavaScript code to check whether a Number is Prime or Not

In this tutorial we will understand how to check a number is prime or not by using javascript.

A prime number is a natural number can be divided by 1 and that has no positive divisors other than 1 and itself.

Let's take an example:

<html>
	<head>
		<script>
			function Prime()
			{
				var i,flag=0,number;
				number = Number(document.getElementById("N").value);

				for(i=2; i <= number/2; i++)
				{
					if(number%i == 0)
					{
						flag = 1;
						break;
					}
				}
				if(flag == 0)
				{
					window.alert("prime number");
				}
				else
				{
					window.alert("not a Prime number");
				}
			}
	</script>
	</head>
	<body>
		<br>
		<h1>Check Whether a number is Prime or not</h1>
		Enter Number :<input type="text" name="n" id = "N"/>
   <button onClick="Prime()">submit</button>
	</body>
</html>
Output:

 

Check Whether a number is Prime or not

Enter Number :