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Is a prime number check in JavaScript

Is a prime number check in JavaScript

Write JavaScript code to check if the given number is a prime number.

When checking if a number num is prime, we only check for factors up to the square root of num. If num has any factors larger than its square root, it must have already been a smaller factor—because factors come in pairs. For example, if 100 = 4 × 25, once you find 4 (which is less than 10 i.e. √100), you’ve already covered the pair (4, 25).

// Check if the given number is a prime number.
function isPrimeNumber(num) {
  if (num < 2) return false;
  const limit = Math.sqrt(num);
  for (let i = 2; i <= limit; i++) {
    if (num % i === 0) return false;
  }
  return true;
}

console.log(isPrimeNumber(37)); // true
console.log(isPrimeNumber(100)); // falseCode language: JavaScript (javascript)
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