How to Calculate the Sum of Array Elements in PHP ?
Given an integer array arr of size n, find the sum of all its elements in PHP.
Example: Consider the below examples:
Input : arr[5] = [ 1, 2, 3, 6, 5 ]
Output : 17
Explanation : 1 + 2 + 3 + 6 + 5 = 17
Input : arr[] = [ 15, 12, 13, 10 ]
Output : 50
There are different methods to calculate the sum of array values:
Table of Content
- Using array_sum() Function
- Using for Loop
- Using array_reduce() Function
- Using Recursion
- Using foreach Loop
Using array_sum() Function
The array_sum() function returns the sum of all the values in an array (one-dimensional and associative). It takes an array parameter and returns the sum of all the values in it.
Syntax
int|float array_sum( array $array );
Example: PHP Program to get the sum of all the Array Elements using the array_sum() Function.
<?php
// Array with values
$arr = [21, 12, 16, 14, 18, 22];
// Calculating sum of array elements
$sumofelements = array_sum($arr);
print_r($sumofelements);
?>
Output
103
Using for Loop
We can use for loop to calculate the sum of array elements. First, we declare a variable and initialize with zero and then loop over array elements and sum up each array element in the declared variable.
Syntax
$sum = 0;
for ( $i = 0; $i < sizeof($arr); $i++ ) {
$sum = $sum + $arr[i];
}
Example: PHP Program to get the sum of all the Array Elements using For Loop.
<?php
$arr = [21, 12, 16, 14, 18, 22];
// Initialize sum with 0
$sum = 0;
// Loop through the array and add
// each element to the sum
for ($i = 0; $i < sizeof($arr); $i++) {
$sum = $sum + $arr[$i];
}
// Display the result
echo "Sum of Array Values:" . $sum;
?>
Output
Sum of Array Values:103
Using array_reduce() Function
The array_reduce() function is used to reduce the array elements into a single value that can be of float, integer or string. The function uses a user-defined callback function to reduce the input array.
Syntax
mixed array_reduce
(
array $array,
callable $callback,
mixed $initial = null
);
Example: PHP Program to get the sum of all the Array Elements using the array_reduce() Function.
<?php
$arr = [21, 12, 16, 14, 18, 22];
// Use array_reduce to calculate the sum
$sum = array_reduce(
$arr,
function ($carry, $elm) {
return $carry + $elm;
},
0
);
// Display the result
echo "Sum of Array Values:" . $sum;
?>
Output
Sum of Array Values:103
Using Recursion
We can use recursion to calculate the sum of array values. The recursive calculates the sum of an array by breaking it down into two cases: the base case, where if the array is empty the sum is 0; and the recursive case, where the sum is calculated by adding the first element to the sum of the remaining elements which is computed through a recursive call with the array shifted by one position and size reduced by one.
Example: PHP Program to get the sum of all the Array Elements using Recursion.
<?php
function sumofElements($arr, $n)
{
// Base or terminating condition
if ($n <= 0) {
return 0;
}
// Calling method recursively
return sumofElements($arr, $n - 1) + $arr[$n - 1];
}
$arr = [21, 12, 16, 14, 18, 22];
$sum = sumofElements($arr, sizeof($arr));
// Display the result
echo "Sum of Array Values:" . $sum;
?>
Output
Sum of Array Values:103
Using foreach Loop
To calculate the sum of array elements in PHP using a `foreach` loop, initialize a sum variable to 0, then iterate through each element of the array, adding its value to the sum. Finally, echo or return the sum.
Example: PHP script sums elements of an array `[1, 2, 3, 4, 5]`, outputs result (`15`) to console using `fwrite(STDOUT, $sum . PHP_EOL);`.
<?php
$array = [1, 2, 3, 4, 5];
$sum = 0;
foreach ($array as $value) {
$sum += $value;
}
// Output the sum to console
fwrite(STDOUT, $sum . PHP_EOL);
?>
Output
15