Find the average of an array in php

In PHP, sometimes we need to perform average operations on arrays to get the average value of specific data. This article will introduce how to find the average of an array using PHP.

Function to calculate the average of an array in PHP

PHP provides us with multiple functions that can be used to calculate the average of an array, which are introduced below.

1. array_sum
   array_sum function is used to return the sum of all values ​​in an array. We can get the average of an array by dividing its sum.

The following is a simple example:

<?php
$numbers = array(1, 2, 3, 4, 5);
$sum = array_sum($numbers);
$count = count($numbers);
$average = $sum / $count;
echo "数组的平均数是： $average";
?>

In the above example, we used the array_sum function to calculate the sum of all values, and the count function to obtain the length of the array (i.e. number of elements), the average of the array can be obtained by dividing the sum by the number of elements.

2. array_reduce
   The array_reduce function can also calculate the sum in an array and also provides greater flexibility. This function uses a callback function to recursively iterate over the entire array elements and calculate them. The callback function receives two parameters: the accumulator and the current element in the array. On each iteration, the callback function returns a new value, which will be assigned to the accumulator, and eventually the accumulator's value will be returned.

Here is an example:

<?php
$numbers = array(1, 2, 3, 4, 5);
$average = array_reduce($numbers, function($carry, $item) {
    return $carry + $item;
}, 0) / count($numbers);
echo "数组的平均数是： $average";
?>

In the above example, we have used the array_reduce function to sum the array elements and set the initial value to 0. Since we already have the sum of the array elements, we just need to divide by the number of array elements to get its average.

3. mean function
   mean function is a function in the PHP array extension library. It can calculate the average of an array, but the corresponding extension library needs to be installed.

Here is an example:

<?php
$numbers = array(1, 2, 3, 4, 5);
$average = mean($numbers);
echo "数组的平均数是： $average";
?>

In the above example, we have used the mean function to calculate the mean of the array. Please note that you need to install the corresponding extension library to use this function.

Summary

In PHP, we can calculate the average of an array using many methods. The array_sum function and the array_reduce function are both good choices for calculating the sum of an array, but the mean function can provide a more convenient method. Using these functions will make array operations simpler, faster, and more efficient.

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