4.2 Reversing an Array (Eloquent JavaScript Solutions)

4-2 Eloquent Javascript Solutions.js

function reverseArray(array) {
  result = [];
  for (let item of array) {
    result.unshift(item);
  }
  return result;
}

function reverseArrayInPlace(array) {
  let len = array.length;
  for (let i = 0; i < Math.floor(len/2); i++) {
    console.log(i, len-i-1, array[i], array[len-i-1], array);
    let swap = array[i];
    array[i] = array[len-i-1];
    array[len-i-1] = swap;
  }
  return array;
}

console.log(reverseArray(["A", "B", "C"]));
// → ["C", "B", "A"];
let arrayValue = [1, 2, 3, 4, 5];
reverseArrayInPlace(arrayValue);
console.log(arrayValue);
// → [5, 4, 3, 2, 1]
let arrayValue2 = [1, 2, 3, 4];
reverseArrayInPlace(arrayValue2);
console.log(arrayValue2);
// → [4, 3, 2, 1]