Javascript:Check numbers are co prime using divisor list

 

function getDivisor(num) {

    let divisor = [];

    for (let i = 2; i <= num; i++) {   // fixed: was i <= num - 1

        if (num % i === 0) {

            divisor.push(i);

        }

    }

    return divisor;

}

function areCoPrime(num1, num2) {

    console.log(`First Number:${num1} Second Number ${num2}`);

    let divisor1 = getDivisor(num1);

    let divisor2 = getDivisor(num2);

    console.log("Divisor", divisor1);

    console.log("Divisor", divisor2);

    let common = divisor1.filter(num => divisor2.includes(num));

    if (common.length > 0) {

        return "Pair is not co-prime";

    } else {

        return "Pair is co-prime";

    }

}

console.log(areCoPrime(6, 9));

// Pair is not co-prime

console.log(areCoPrime(8, 15));

// Pair is co-prime

console.log(areCoPrime(7, 11));

// Pair is co-prime

console.log(areCoPrime(5, 10));

// Pair is not co-prime (this one was wrong before)

console.log(areCoPrime(7, 7));

// Pair is not co-prime (this one was wrong before)

Javascript:Check numbers are co prime using gcd

function gcd(a, b) {

  a = Math.abs(a);

  b = Math.abs(b);

  while (b !== 0) {

    [a, b] = [b, a % b];

  }

  return a;

}

function areCoPrime(num1, num2) {

  if (!Number.isInteger(num1) || !Number.isInteger(num2)) {

    throw new TypeError("Both arguments must be integers");

  }

  return gcd(num1, num2) === 1;

}

console.log(areCoPrime(6, 9));   // false (gcd = 3)

console.log(areCoPrime(8, 15));  // true  (gcd = 1)

console.log(areCoPrime(7, 11));  // true  (gcd = 1)

console.log(areCoPrime(5, 10));  // false (gcd = 5, the case your old code got wrong)

console.log(areCoPrime(7, 7));   // false (gcd = 7)