Selection Sort in JavaScript

Question

function newsort(arr, left, right){    

for(var i= left; i < right; ++i){
    var min = i;
    for (var j = i; j < right; ++j){
        if (arr[min] > arr[         


        

Answer 1

var selectionSort = function(array){
  for(var i = 0; i < array.length; i++){
    //set min to the current iteration of i
    var min = i;
    for(var j = i+1; j < array.length; j++){
      if(array[j] < array[min]){
       min = j;
      }
    }
    var temp = array[i];
    array[i] = array[min];
    array[min] = temp;
  }
  return array;
};
var array = [3,2,10,1]
console.log('selectionSort should return [1,2,3,10]-->',selectionSort(array));

It might be easier to reason with if you use a helper swap function:

//HELPER FUNCTION
var swap = function(array, firstIndex, secondIndex){
    var temp = array[firstIndex];
    array[firstIndex]  = array[secondIndex];
    array[secondIndex] = temp;
};
var array = [2,1];
swap(array, 0, 1)
console.log('swap should return [1,2] -->', array);


var selectionSort = function(array){
  for(var i = 0; i < array.length; i++){
    //set min to the current iteration of i
    var min = i;
    for(var j = i+1; j < array.length; j++){
      if(array[j] < array[min]){
        min = j;
      }
    }
    swap(array, i, min);
  }
  return array;
};
var array = [3,2,10,1]
console.log('selectionSort should return [1,2,3,10]-->',selectionSort(array));

Visual of selection sort:

[3,1,2]
 |-----> iterate over list. find that min = 1 so we swap current i (3) with min(1)

[1,3,2]
   |---> iterate over list. find that min = 2 so we swap current i (3) with min(2)

[1,2,3]
     |---> iterate over list. find that min = 3 so we swap current i (3) with min(3)