Filter array in place

filterarrayinplace.js

function filterInPlace(array, condition) {
  let iOut = 0;
  for (let i = 0; i < array.length; i++) {
    if (condition(array[i])) {
      array[iOut++] = array[i];
    }
  }

  array.length = iOut;
}

const arr = [];
for (let i = 0; i<100; i++) {
  arr.push(i);
}

filterInPlace(arr, (n) => n % 2); // [0,2,4,6...]

this modifies the array in place to save memory, and performant