How to Count Array Elements, Unique Values, and Occurrences in PHP

In PHP, arrays are a fundamental data type, and counting elements can be done with built-in functions. The article covers three main tasks: counting total elements, counting distinct elements, and counting occurrences of a specific element.

1. Counting the total number of array elements

The count() function returns the number of elements in an array.

$fruits = array("apple", "orange", "banana", "pear");
echo count($fruits); // outputs 4

2. Counting distinct elements in an array

The array_count_values() function returns a new array where each key is a unique value from the original array and each value is the number of times that key appears.

$fruits = array("apple", "orange", "banana", "pear", "apple", "apple");
$count_fruits = array_count_values($fruits);
print_r($count_fruits);
/* Output:
Array (
    [apple] => 3
    [orange] => 1
    [banana] => 1
    [pear] => 1
) */

3. Counting occurrences of a specific element

One approach uses a foreach loop to iterate the array and increment a counter when the target value is found.

$fruits = array("apple", "orange", "banana", "pear", "apple", "apple");
$count_apple = 0;
foreach ($fruits as $fruit) {
    if ($fruit == "apple") {
        $count_apple++;
    }
}
echo $count_apple; // outputs 3

Another approach combines array_filter() with an anonymous function to keep only the desired elements, then uses count() to get the total.

$fruits = array("apple", "orange", "banana", "pear", "apple", "apple");
$count_apple = count(array_filter($fruits, function($fruit) {
    return $fruit == "apple";
}));
echo $count_apple; // outputs 3

In summary, PHP offers several ways— count(), array_count_values(), foreach loops, and array_filter() with anonymous functions—to count array elements, distinct values, or specific occurrences, allowing developers to choose the most suitable method for their needs.