Implementation of Fisher-Yates in Javascript to shuffle an array

shuffle.js

function fisherYates(array) {
  let i = array.length;
  let temp, j;
  
  while(i) {
    j = (Math.random() * i--) | 0;  // x | 0 gives floor(x)
    
    // swap elements i & j
    temp = array[i];
    array[i] = array[j];
    array[j] = temp;
  }
}


// A note on the implementation:
// Although we want to start with the last element of the array (i.e.
// i = array.length - 1), by starting with i = array.length (not
// minus 1), we can randomly generate j without the need to perform an
// addition, thus saving an operation

function fisherYatesAlternative(array) {
  let temp, j;
  
  for (let i = array.length - 1; i >= 0; i--) {
    j = Math.floor(Math.random() * i + 1);
    
    // swap elements i & j
    temp = array[i];
    array[i] = array[j];
    array[j] = temp;
  }
}

nums = [1,2,3,4,5,6,7]
fisherYates(nums);
console.log(nums)

fisherYatesAlternative(nums);
console.log(nums)

// See: https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle