PHP array sum function

PHP is a server-side scripting language widely used for web development and is open source software. It can be embedded in HTML and supports object-oriented programming as well. When we develop web applications, we often need to operate on arrays, such as summing arrays. Below I will introduce how to find the sum of an array in PHP.

1. Use a for loop to find the sum of an array

In PHP, the simplest way to find the sum of an array is to use a for loop. The for loop iterates through each array element, accumulates the value of the element into a variable, and finally returns the value of the variable. The following is the code using a for loop:

function array_sum_for($arr) {
    $sum = 0;
    for ($i = 0; $i < count($arr); $i++) {
        $sum += $arr[$i];
    }
    return $sum;
}

This function accepts an array as a parameter, uses a for loop to traverse the array and accumulate the array elements into a variable $sum, and finally returns $sum.

2. Use a while loop to calculate the sum of an array

You can use a while loop to calculate the sum of an array. This method is very similar to a for loop. The following is the code using the while loop:

function array_sum_while($arr) {
    $sum = 0;
    $i = 0;
    while ($i < count($arr)) {
        $sum += $arr[$i];
        $i++;
    }
    return $sum;
}

This function also accepts an array as a parameter, uses the while loop to traverse the array and accumulate the array elements into a variable $sum, and finally returns $sum.

3. Use array_reduce function to find the sum of arrays

PHP provides an array_reduce function, which can be used to perform simple calculations on arrays. This function requires two parameters, the first parameter is the array to be calculated, and the second is a callback function. The callback function requires two parameters, the first parameter is the accumulator, and the second parameter is the value of the current element. The following is the code using the array_reduce function:

function array_sum_reduce($arr) {
    return array_reduce($arr, function($sum, $value) {
        return $sum + $value;
    });
}

This function also accepts an array as a parameter and uses the array_reduce function to calculate the array. The callback function accumulates the value of each array element and ultimately returns the sum.

4. Use the array_sum function to find the sum of an array

PHP also provides a built-in array_sum function for calculating the sum of an array. This function only takes an array as argument and returns the sum of its elements. The following is the code using the array_sum function:

function array_sum_builtin($arr) {
    return array_sum($arr);
}

This function directly calls PHP's array_sum function, passing the array as a parameter to the function, and ultimately returns the sum of the array elements.

Summary

This article introduces four methods to find the sum of an array in PHP, including using for loop, while loop, array_reduce function and array_sum function. In actual development, which method to use depends on the developer's personal preferences and specific application scenarios.

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