How do I check if a number is a prime number in JavaScript?
Rashid D

To check if a number is a prime number in JavaScript, you can use a loop to test if it is divisible by any number other than 1 and itself. Here's a step-by-step guide on how to achieve this: 1. Define the number you want to check:

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   const number = 13;

Replace13 with the actual number you want to check. 2. Implement the prime number checking logic:

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   function isPrime(number) {
     // Check if number is less than 2
     if (number < 2) {
       return false;
     }

     // Loop through numbers from 2 to the square root of the number
     for (let i = 2; i <= Math.sqrt(number); i++) {
       if (number % i === 0) {
         return false; // Number is divisible by another number, not prime
       }
     }

     return true; // Number is prime
   }

   const isPrimeNumber = isPrime(number);
   console.log(isPrimeNumber);

In this example, theisPrime() function takes thenumber as an argument. It first checks if the number is less than 2, as prime numbers must be greater than or equal to 2. Then, it loops through numbers from 2 up to the square root of the number. If the number is divisible by any of these numbers, it is not a prime number andfalse is returned. If the loop completes without finding any divisors, the number is considered prime andtrue is returned. 3. Display the result: Use the result of the prime number check to inform the user whether the number is prime or not.

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   console.log(`${number} is ${isPrimeNumber ? 'prime' : 'not prime'}`);

This example logs a message indicating whether the number is prime or not to the console. By following these steps, you can check if a number is a prime number in JavaScript. Adjust the code as needed to fit your specific use case and handle different numbers.

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