How to sort an array based on the length of each element?

Question

I have an array like this:

arr = []
arr[0] = \"ab\"
arr[1] = \"abcdefgh\"
arr[2] = \"abcd\"

After sorting, the output array should be:

Answer 1

I adapted @shareef's answer to make it concise. I use,

.sort(function(arg1, arg2) { return arg1.length - arg2.length })

Answer 2

Here is the sort, depending on the length of a string with javascript as you asked:

[the solution of the problem by bubble sort][1]

[1]: http://jsfiddle.net/sssonline2/vcme3/2/enter code here

Answer 3

We can use Array.sort method to sort this array.

ES5 solution

var array = ["ab", "abcdefgh", "abcd"];

array.sort(function(a, b){return b.length - a.length});

console.log(JSON.stringify(array, null, '\t'));

For ascending sort order: a.length - b.length

For descending sort order: b.length - a.length

ES6 solution

Attention: not all browsers can understand ES6 code!

In ES6 we can use an arrow function expressions.

let array = ["ab", "abcdefgh", "abcd"];

array.sort((a, b) => b.length - a.length);

console.log(JSON.stringify(array, null, '\t'));

Answer 4

This code should do the trick:

var array = ["ab", "abcdefgh", "abcd"];

array.sort(function(a, b){return b.length - a.length});

console.log(JSON.stringify(array, null, '\t'));

Answer 5

Based on Salman's answer, I've written a small function to encapsulate it:

function sortArrayByLength(arr, ascYN) {
        arr.sort(function (a, b) {           // sort array by length of text
            if (ascYN) return a.length - b.length;              // ASC -> a - b
            else return b.length - a.length;                    // DESC -> b - a
        });
    }

then just call it with

sortArrayByLength( myArray, true );

Note that unfortunately, functions can/should not be added to the Array prototype, as explained on this page.

Also, it modified the array passed as a parameter and doesn't return anything. This would force the duplication of the array and wouldn't be great for large arrays. If someone has a better idea, please do comment!

Answer 6

If you want to preserve the order of the element with the same length as the original array, use bubble sort.

Input = ["ab","cdc","abcd","de"];

Output  = ["ab","cd","cdc","abcd"]

Function:

function bubbleSort(strArray){
  const arrayLength = Object.keys(strArray).length;
    var swapp;
    var newLen = arrayLength-1;
    var sortedStrArrByLenght=strArray;
    do {
        swapp = false;
        for (var i=0; i < newLen; i++)
        {
            if (sortedStrArrByLenght[i].length > sortedStrArrByLenght[i+1].length)
            {
               var temp = sortedStrArrByLenght[i];
               sortedStrArrByLenght[i] = sortedStrArrByLenght[i+1];
               sortedStrArrByLenght[i+1] = temp;
               swapp = true;
            }
        }
        newLen--;
    } while (swap);
  return sortedStrArrByLenght;
}