The JavaScript Array.sort() method is used to sort the array elements in place and returns the sorted array. This function sorts the elements in string format. It will work well for string arrays but not for numbers. For example: if numbers are sorted as strings then “75” is bigger than “200”.
Example: In this example, the Array sort() method is implemented. The array is sorted as a string.
Javascript
let arr = [12, 25, 31, 23, 75, 81, 100]console.log(arr.sort()) |
Output:
// code shows this output
Wrong Output : [100, 12, 23, 25, 31, 75, 81]
// Correct Output
Correct Output : [12, 23, 25, 31, 75, 81, 100]
Example: This example sorts the array elements in string format.
javascript
// Declare and initialize original arraylet marks = [12, 25, 31, 23, 75, 81, 100];// Print Before Sorting Array console.log("Original Array");console.log(marks);// Call sort functionmarks.sort();console.log("After Sorting in Ascending Order");// Print Sorted Numeric Array console.log(marks); |
Output:
Original Array
12,25,31,23,75,81,100
After Sorting in Ascending Order
100,12,23,25,31,75,81
Then, how to sort number array elements?
There are two approaches to sorting the number array in ascending order.
- Using Compare Function
- By Creating Loops
Approach 1: Using Compare Function
We can create a Compare function that returns negative, zero, or positive values.
Syntax:
function(a, b){return a - b}
- Negative Value ( a < b) => a will be placed before b
- zero value (a == b) => No Change
- Positive Value (a > b ) => a will be placed after b
Example: This example uses compare function to sort the array elements in ascending order.
javascript
// Declare and initialize an Arraylet marks = [12, 25, 31, 23, 75, 81, 100];// Print Before sorting array console.log("Original Array");console.log(marks);// Sort elements using compare method marks.sort(function (a, b) { return a - b });console.log("After sorting in Ascending order");// Print sorted Numeric array console.log(marks); |
Original Array [ 12, 25, 31, 23, 75, 81, 100 ] After sorting in Ascending order [ 12, 23, 25, 31, 75, 81, 100 ]
Now, we would like to sort the array in Descending order then we have to change the compare function.
Syntax:
function(a, b){return b - a}
- Negative Value ( b < a) => a will be Placed after b
- zero value (a == b) => No Change
- Positive Value (b > a ) => a will be placed before b
Example: This example uses compare function to sort the array elements in descending order.
javascript
// Declare and initialize an Arraylet marks = [12, 25, 31, 23, 75, 81, 100];// Print Before sorting array console.log("Original Array");console.log(marks);// Sort elements using compare method marks.sort(function (a, b) { return b - a });console.log("After sorting in Ascending order");// Print sorted Numeric array console.log(marks); |
Original Array [ 12, 25, 31, 23, 75, 81, 100 ] After sorting in Ascending order [ 100, 81, 75, 31, 25, 23, 12 ]
Approach 2: Creating Loops
We can also use loops to sort the array elements. Here, we will use bubble sort (a simple sorting technique) to sort the array elements in ascending order.
Example:
javascript
// Sorting functionfunction Numeric_sort(ar) { let i = 0, j; while (i < ar.length) { j = i + 1; while (j < ar.length) { if (ar[j] < ar[i]) { let temp = ar[i]; ar[i] = ar[j]; ar[j] = temp; } j++; } i++; }}// Original Arraylet arr = [1, 15, 10, 45, 27, 100];// Print Before sorting array console.log("Original Array");console.log(arr);// Function call Numeric_sort(arr);console.log("Sorted Array");// Print sorted Numeric array console.log(arr); |
Output:
Original Array
1,15,10,45,27,100
Sorted Array
1,10,15,27,45,100