Question

How to find the max prime number in an array with JavaScript

Answer 1

function isPrime(n) { 
    if (n === 0) return 0;
    if (n === 1) return 0;
    
    for (let i = 2; i <= Math.sqrt(n); i++) {
        if (n % i === 0)
            return 0;
    }
    
    return 1;
}
 
 
const arr = [4, 8, 17, 5, 9, 22, 21, 13, 18, 99];
let max = arr[0];
  
for (let i = 0; i < arr.length; i++) {
      if (isPrime(arr[i])) { // 17 5 13
          if (max < arr[i]) { 
              max = arr[i];
          }
      }
}       
 
console.log(max);
 
 
 
/*
 
17 
     
*/

 

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