# JavaScript: Check a number is prime or not

## JavaScript Function: Exercise-8 with Solution

Write a JavaScript function that accepts a number as a parameter and check the number is prime or not.

Note : A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.

Pictorial Presentation:

Sample Solution: -

HTML Code:

``````<!DOCTYPE html>
<html>
<meta charset=utf-8 />
<title>Check a number is prime or not</title>
<body>

</body>
</html>
```
```

JavaScript Code:

``````function test_prime(n)
{

if (n===1)
{
return false;
}
else if(n === 2)
{
return true;
}else
{
for(var x = 2; x < n; x++)
{
if(n % x === 0)
{
return false;
}
}
return true;
}
}

console.log(test_prime(37));
```
```

Sample Output:

```true
```

Flowchart:

Live Demo:

See the Pen JavaScript -Counts the number of vowels within a string-function-ex- 7 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

What is the difficulty level of this exercise?

﻿

## JavaScript: Tips of the Day

Set object

```const set = new Set([1, 1, 2, 3, 4]);

console.log(set);
```

The Set object is a collection of unique values: a value can only occur once in a set.
We passed the iterable [1, 1, 2, 3, 4] with a duplicate value 1. Since we cannot have two of the same values in a set, one of them is removed. This results in {1, 2, 3, 4}.

Ref: https://bit.ly/323Y0P6