My math.pow is return NaN when I call it on an array with numerical values. How do I get the square of an array element

Question

I have a function with an array of numbers, I want to square it but I want them in the array box like [4,9,16] Each time i try to do that, it throws back a NAN output in the console. The numbers come back listed as in a straight line.

digit = (num) => {
  let digits = String(num).split('').map(Number);
  for (let i = 0; i < digits.length; i++) {
    let square = Math.pow(digits, 2);
    console.log(square);
  }
};
digit(234);

output: NaN

digit = (num) => {
  let digits = String(num).split('').map(Number);

  for (let i = 0; i < digits.length; i++) {
    let square = Math.pow(digits[i], 2);
    console.log(square);
  }
};
digit(234);

output: 4 9 16

Is it possible to have my output as [4,9,16]?

Answer 1

What you want to do here is to modify the array in place, so you need to assign the result of Math.pow() to each element of the array.

 digit = (num) => { let digits = String(num).split("").map(Number); for(let i = 0; i < digits.length; i++) { digits[i] = Math.pow(digits[i], 2); } console.log(digits); }; digit(234);

After the for loop is done, then each array item will be squared.

Answer 2

Math.pow() expects two inputs, both of which should be numbers (not arrays)

You need to loop through your digits, and push the values to an array.

Something like this:

function digit(num) {
    let digits = String(num).split('')
    .map(Number);
    let square = [] // Define an empty array outside the loop
    for(let i = 0; i < digits.length; i++){
        square.push(Math.pow(digits[i],2)); //Push each value to the loop
    }
    return square; //Return the modified array after the loop
}

console.log(digit(234)); //Outputs [4, 9, 16]