PHP array_sum Function

last modified March 13, 2025

The PHP array_sum function calculates the sum of values in an array. It's a convenient way to add up numeric values without manual iteration.

Basic Definition

The array_sum function returns the sum of values in an array. It converts non-numeric values to numbers (0 for non-convertible values).

Syntax: array_sum(array $array): int|float. The function returns an integer or float depending on the array values. Empty arrays return 0.

Basic array_sum Example

This demonstrates summing a simple array of integers to get a total.

basic_array_sum.php

<?php

$numbers = [10, 20, 30, 40];
$total = array_sum($numbers);

echo "The sum is: " . $total;

This adds all numbers in the array. The function handles the iteration and summation automatically, returning the combined total of all elements.

Summing Floating Point Numbers

array_sum works with floating-point numbers, returning a float.

float_sum.php

<?php

$prices = [12.99, 9.99, 24.50, 5.75];
$totalPrice = array_sum($prices);

echo "Total price: $" . number_format($totalPrice, 2);

This calculates the sum of product prices. The result is a float value that we format to two decimal places for proper monetary display.

Handling Mixed Numeric Types

The function automatically handles arrays containing both integers and floats.

mixed_types.php

<?php

$values = [5, 10.5, "15", "20.25"];
$sum = array_sum($values);

echo "Mixed sum: " . $sum;

Numeric strings are converted to numbers. The function returns a float since some values contain decimal points, maintaining precision in the result.

Non-Numeric Values Behavior

Non-numeric values are treated as 0 in the summation process.

non_numeric.php

<?php

$mixed = [10, "apple", 20, "orange", 5.5];
$result = array_sum($mixed);

echo "Sum with non-numerics: " . $result;

String values that can't be converted to numbers are treated as 0. Only the numeric values (10, 20, 5.5) contribute to the final sum in this example.

Empty Array Handling

When passed an empty array, array_sum returns 0 by default.

empty_array.php

<?php

$empty = [];
$sum = array_sum($empty);

echo "Empty array sum: " . $sum;

This behavior is useful when working with dynamically generated arrays that might be empty, preventing the need for special empty array checks.

Best Practices

Type Checking: Validate array contents if strict typing is needed.
Precision: Be aware of floating-point precision limitations.
Large Arrays: Works efficiently even with large arrays.
Error Handling: Consider checking array contents for non-numeric values.

Source

PHP array_sum Documentation

This tutorial covered the PHP array_sum function with practical examples showing its usage for various array summation scenarios.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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