w3resource
JavaScript Exercises

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:

JavaScript: Check a number is prime or not

Sample Solution: -

HTML Code:

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

Flowchart: JavaScript function: Check a number is prime or not

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

Previous: Write a JavaScript function that accepts a string as a parameter and counts the number of vowels within the string.
Next: Write a JavaScript function which accepts an argument and returns the type.

What is the difficulty level of this exercise?