How Can You Sort a Two-Dimensional Array by Column Value in JavaScript?

Sorting Two-Dimensional Arrays by Column Values in JavaScript

In this article, we will explore how to sort a two-dimensional array in JavaScript by a specific column value.

Problem Statement

Given a two-dimensional array represented as an array of arrays, each sub-array containing two elements, the task is to sort the array in ascending order based on the values in the first column (column with index 0).

Solution

JavaScript provides a convenient method, sort(), that can be utilized to sort multidimensional arrays. Let's break down the provided code:

var a = [[12, 'AAA'], [58, 'BBB'], [28, 'CCC'],[18, 'DDD']];

a.sort(sortFunction);

function sortFunction(a, b) {
    if (a[0] === b[0]) {
        return 0;
    }
    else {
        return (a[0] < b[0]) ? -1 : 1;
    }
}

Explanation

• The sort() method is invoked on the a array.

• The sortFunction is passed as the argument to the sort() method. This function compares two sub-arrays' first elements (a[0] and b[0]) and returns:

  • 0 if they are equal.
  • -1 if a[0] is less than b[0].
  • 1 if a[0] is greater than b[0].

By default, sort() uses the returned values to determine the ordering of the sub-arrays, sorting them in ascending order.

Sorting By Second Column

To sort by the second column, the sortFunction can be modified to compare second column values:

a.sort(compareSecondColumn);

function compareSecondColumn(a, b) {
    if (a[1] === b[1]) {
        return 0;
    }
    else {
        return (a[1] < b[1]) ? -1 : 1;
    }
}

This enables flexibility in sorting by different columns based on the specific requirements.

The above is the detailed content of How Can You Sort a Two-Dimensional Array by Column Value in JavaScript?. For more information, please follow other related articles on the PHP Chinese website!