array modifier - mid exam

function arrayModifier(input) {
    let array = input.shift().split(" ").map(Number);
   // console.log(array);
   let command = input.shift();
   while (command !== "end") {
       let tokens = command.split(" ");
       switch (tokens[0]) {
           case "swap":
               swap(array, index1, index2)
               break;
            case "multiply":
                multiply(array, index1, index2);
                break;

           case "decrease":
               decrease(array);
               break;
       }

   function swap(list, index1, index2) {
       let index1 = Number(tokens[1]);
       let index2 = Number(tokens[2]);
        array[index1] = array[index2];
        array[index2] = temp;
        break;
}
function multiply(list, index1, index2) {
    let index1 = Number(tokens[1]);
    let index2 = Number(tokens[2]);
    array[index1] *= array[index2];
    break;
}
function decrease(list) {
array = array.map(x => --x);
}
command = input.shift();

}
console.log(array.join(", "));
}

arrayModifier([
    '23 -2 321 87 42 90 -123',
    'swap 1 3',
    'swap 3 6',
    'swap 1 0',
    'multiply 1 2',
    'multiply 2 1',
    'decrease',
    'end'
  ]);