How to Find Sum of Array in PHP: Simple Guide

To find the sum of an array in PHP, use the array_sum() function which adds all the values in the array and returns the total. Simply pass your array as an argument to array_sum() to get the sum.

Syntax

The syntax to find the sum of an array in PHP is simple:

• array_sum(array $array): int|float

Here, $array is the array of numbers you want to add. The function returns the total sum of all values.

php

array_sum(array $array): int|float

Example

This example shows how to use array_sum() to add numbers in an array and print the result.

php

<?php
$numbers = [10, 20, 30, 40];
$total = array_sum($numbers);
echo "The sum is: " . $total;
?>

Output

The sum is: 100

Common Pitfalls

Common mistakes include passing non-numeric values or forgetting that array_sum() only sums values, not keys.

Also, if the array is empty, array_sum() returns 0.

php

<?php
// Wrong: summing keys instead of values
$array = [1 => 10, 2 => 20, 3 => 30];
// This sums values, not keys
$sum = array_sum($array);
echo "Sum of values: " . $sum . "\n";

// Right: if you want to sum keys, use array_keys()
$sumKeys = array_sum(array_keys($array));
echo "Sum of keys: " . $sumKeys;
?>

Output

Sum of values: 60
Sum of keys: 6

Quick Reference

Function	Description
array_sum($array)	Returns the sum of all values in the array
array_keys($array)	Returns all keys of the array (useful if you want to sum keys)
empty array	Returns 0 when passed to array_sum()

Key Takeaways

Use array_sum() to quickly find the sum of all values in a PHP array.

array_sum() returns 0 for empty arrays, so no errors occur.

array_sum() sums values, not keys; use array_keys() if you want to sum keys.

Passing non-numeric values may lead to unexpected results or warnings.

Always ensure your array contains numbers to get correct sums.