Learn How to Write a PHP Function to Compute Combinations from Multiple Groups

A Guide to Calculating Permutations with Variable Arguments

Photo by Dan Cristian Pădureț on Unsplash

Introduction

In this tutorial, we’ll explore a PHP programming problem that involves calculating the number of permutations (combinations) of choices you would have if you selected one item from each group. We’ll create a function that takes a variable number of arguments, each argument representing the number of items in a group.

By the end of this post, you’ll have a better understanding of how to work with variable arguments, loops, and mathematical operations in PHP.

Step 1: Defining the Function

First, let’s define a function called combinations that takes a variable number of arguments using the … syntax:

function combinations(...$args) {
  // Calculate the number of permutations (combinations)
}

Step 2: Calculating the Number of Permutations (Combinations)

We’ll use a loop to iterate through the arguments and multiply the number of items in each group. We’ll initialize a variable called total to store the running product of the number of items in each group: