Array ReOrdering - Sort

        In Javascript , the items are sorted as strings by default. So if you try to sort an array with have integer value, it will return incorrect result. See below example,

let arr = [ 1, 2, 7,15, 18 ];

arr.sort();

alert( arr );  // 1,15,18,2,7(Wrong Result)

The above example returns a wrong result. Because as I said earlier, sorted by string is default.

Remember, internally it will convert as string.

1. Classical Trick

function compareNumeric(a, b) {
  if (a > b) return 1;
  if (a == b) return 0;
  if (a < b) return -1;
}

let arr = [ 1, 2, 15, 7, 19, 54, 87, 43 ];
arr.sort(compareNumeric);
alert(arr);  // 1,2,7,15,19,43,54,87

2. With simple comparison

let arrSort = [ 1, 2, 15, 76, 76, 34, 89, 12 ];

arrSort.sort(function(a, b) { return a - b; }); // Ascending

alert(arrSort);

Note: For descending use b-a.

3. Same with Arrow function

let arrSort = [ 1, 2, 15, 76, 76, 34, 89, 12 ];

arrSort.sort( (a, b) => a - b );

alert(arrSort);

Conclusion:

Here all the example is only for integer array. Suppose If you want to sort an string array, no need to worry about above logic. Simply you can call sort method directly.