Codewars for ever

directionsReduction.js

// solution initial
function dirReduc(arr) {
  while (true) {
    for (let i = 0; i < arr.length - 1; i++) {
      if (
        (arr[i] === 'NORTH' && arr[i + 1] === 'SOUTH') ||
        (arr[i] === 'SOUTH' && arr[i + 1] === 'NORTH') ||
        (arr[i] === 'EAST' && arr[i + 1] === 'WEST') ||
        (arr[i] === 'WEST' && arr[i + 1] === 'EAST')
      ) {
        arr[i] = 0;
        arr[i + 1] = 0;
      }
    }
    if (arr.indexOf(0) === -1) break;
    arr = arr.filter((item) => item !== 0);
  }
  return arr;
}

// dirReduc(["NORTH", "SOUTH", "SOUTH", "EAST", "WEST", "NORTH", "WEST"]) =>  ["WEST"]
// dirReduc(["NORTH", "WEST", "SOUTH", "EAST"]) => ["NORTH", "WEST", "SOUTH", "EAST"]
// dirReduc(["NORTH", "SOUTH", "EAST", "WEST", "EAST", "WEST"]) => []