Combining array_column and array_count_values to count the frequency of a column value

M66 2025-04-28

How to combine PHP's array_column and array_count_values functions to count the frequency of a column value in an array?

In PHP, we can efficiently count the frequency of the occurrence of a specific column in a multidimensional array by combining the array_column and array_count_values functions. Next, we will introduce the functions of these two functions in detail and use an example to illustrate how to complete this task.

1. Introduction to array_column function

The array_column function is used to extract the value of a column from a multidimensional array. Its syntax is as follows:

 array_column(array $array, mixed $column_key, mixed $index_key = null): array

$array : The input multi-dimensional array.
$column_key : The key name of the column we want to extract.
$index_key : Optional parameter, specifying the new index key (if required).

This function returns a one-dimensional array containing all values of the specified column.

2. Introduction to array_count_values function

The array_count_values function is used to count the number of occurrences of each value in an array and returns an associative array where the key is the value in the array and the value is the number of occurrences of the value. The syntax is as follows:

 array_count_values(array $array): array

3. Use array_column and array_count_values to achieve frequency statistics

Suppose we have a multidimensional array containing user information and we want to count the frequency of the gender column value in it. We can use array_column to extract the gender column, and then use array_count_values to count the frequency of each gender.

Sample code

 <?php

// Sample data：Includes the user&#39;s name and gender
$users = [
    ['name' => 'Alice', 'gender' => 'female'],
    ['name' => 'Bob', 'gender' => 'male'],
    ['name' => 'Charlie', 'gender' => 'male'],
    ['name' => 'David', 'gender' => 'male'],
    ['name' => 'Eve', 'gender' => 'female']
];

// use array_column extract gender List
$genders = array_column($users, 'gender');

// use array_count_values Statistical gender frequency
$genderCount = array_count_values($genders);

// Output statistics
print_r($genderCount);

?>

Output result

 Array
(
    [female] => 2
    [male] => 3
)

4. Code description

We first define a multi-dimensional array $users containing user information, each element is an associative array containing name and gender keys.
Use array_column($users, 'gender') to extract the gender of all users and get a simple one-dimensional array: ['female', 'male', 'male', 'male', 'female'] .
Use array_count_values($genders) to count the frequency of gender. The result is an associative array that represents the number of occurrences of each gender.

5. Use scenarios

This method is very suitable for handling large amounts of multi-dimensional array data, especially when you need to perform frequency statistics on the value of a certain column. For example, statistical product classification, user gender, order payment methods, etc.

6. Summary

By combining PHP's array_column and array_count_values functions, we can easily count the frequency of values of a column in an array. The use of these two makes processing array data simple and efficient. With this technique, you can easily analyze and count various data to improve development efficiency.

Combining array_column and array_count_values ​​to count the frequency of a column value