JavaScript: Check every numbers are prime or not in an array

JavaScript Array: Exercise-48 with Solution

Check All Numbers Prime

Write a JavaScript program that takes an array of integers and returns false if every number is not prime. Otherwise, return true.

Test Data:

([2,3,5,7]) -> true
([2,3,5,7,8]) -> false

Sample Solution-1:

JavaScript Code :

// Function to check if all numbers in an array are prime
function test(arr_nums) {
  // Iterate through each number in the array
  for (n of arr_nums) {
    // Check if the number is equal to 1 or greater than 2 and divisible by 2
    if (n == 1 || (n > 2 && n % 2 == 0)) 
      // Return false if the condition is met for any number
      return false;
  }
  // Return true if none of the numbers meet the specified condition
  return true;
}

// Test the function with an array of prime numbers
nums = [2, 3, 5, 7];
console.log("Original array of integers: " + nums);
console.log("In the said array, check if every number is prime or not: " + test(nums));

// Test the function with an array containing a non-prime number (8)
nums = [2, 3, 5, 7, 8];
console.log("Original array of integers: " + nums);
console.log("In the said array, check if every number is prime or not: " + test(nums));

Output:

Original array of integers: 2,3,5,7
In the said array check every numbers are prime or not! true
Original array of integers: 2,3,5,7,8
In the said array check every numbers are prime or not! false

Flowchart :

Live Demo :

See the Pen javascript-array-exercise-48 by w3resource (@w3resource) on CodePen.

Sample Solution-2:

JavaScript Code :

// Function to check if all numbers in an array are prime
function test(arr_nums) {
  // Use the every method to check the primality of each number in the array
  return arr_nums.every(n => !'1'.repeat(n).match(/^1?$|^(11+?)\1+$/));
}

// Test the function with an array of prime numbers
nums = [2, 3, 5, 7];
console.log("Original array of integers: " + nums);
console.log("In the said array, check if every number is prime or not: " + test(nums));

// Test the function with an array containing a non-prime number (8)
nums = [2, 3, 5, 7, 8];
console.log("Original array of integers: " + nums);
console.log("In the said array, check if every number is prime or not: " + test(nums));

Output:

Original array of integers: 2,3,5,7
In the said array check every numbers are prime or not! true
Original array of integers: 2,3,5,7,8
In the said array check every numbers are prime or not! false

Flowchart :

Live Demo :

See the Pen javascript-array-exercise-48-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that checks if every number in an array is prime using a helper isPrime function.
• Write a JavaScript function that uses the every() method to determine if all numbers in an array are prime.
• Write a JavaScript function that iterates over an array and returns false immediately if a non-prime is found.
• Write a JavaScript function that validates an array's numeric elements and returns true only if all are prime.

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