Discussion on: Bubble Sorting for Beginners in JS

[Hans]

I just modified yours and was curious what would happen if I used ~500 random numbers, assigned to const and frozen... Using object.freeze alone makes a such a MASSIVE impact, I didn't realize...

// RESOURCES:
// 
// Video Describing Bubble Sort Process
//    https://www.youtube.com/watch?v=6Gv8vg0kcHc
// IIFE Stuff
//    https://flaviocopes.com/javascript-iife/
// Bubble Sorting Post & Discussion (Read Comments!)
//    https://dev.to/ryan_dunton/bubble-sorting-for-beginners-in-js-2opp 
// Destructuring
//    https://hackernoon.com/temporary-swap-vs-xor-swap-vs-destructuring-assignment-easy-swap-7e3f1f047db5


// generate random numbers (not concerned about performance here)
        var arr = [];
        for (var i = 0; i < 500; i++)
        {
            arr.push(Math.floor(Math.random() * 499) + 1)
        }
        console.log(arr);

/*
1. use const to avoid reassignment mutations and 
2. lock it dock further by freezing the object... (speeds it up 4x)
   Comment out object.freeze to see a massive drop in preformance...
3. TODO: Experiment with TypedArrays and fill method ?
*/
// const data = [1, 2, 6, 9, 4, 1, 2, 3, 5, 67, 8, 9, 2, 23, 5, 67, 7, 678, 2, 12, 34, 546, 567, 678, 890, 678, 34, 3453, 123, 345, 46, 57, 678, 4];
const data = arr;
Object.freeze(data);

// use a function expression to avoid hoisting & const to avoid global namespace of function name
const bubbleSort = (arr) => {
  // use map instead of loop to use temp values & avoid mutations of original data.
  arr.map(ary => {
    arr.map((num, i) => {
      // compare arr[i] (left) with arr[i + 1] (right)
      // if left is greater than right, swap them via destructuring
      if (arr[i] > arr[i + 1]) {
       [arr[i+1], arr[i] ] = [arr[i], arr[i+1]]; 
      }
    })
  })
  return arr;
};

/*
PERF TESTING: 
132 Originally... 
408 By freezing the array...
1. ; Prevents issues when blindly concatenating two JavaScript files
2. Wrapped code to avoid issues with global scop, for quicker experiment
*/
;((a)=> {
  /* */
  let operations = 0;
  const bubbleSort = (arr) => {
    arr.map(ary => {
      arr.map((num, i) => {
        if (arr[i] > arr[i + 1]) {
          [arr[i+1], arr[i] ] = [arr[i], arr[i+1]]; 
          operations++;
        }
      })
    })
    return arr;
  }
  bubbleSort(a)
  console.log('Operations: ' + operations)
})(data)