How to Use PHP's array_column Function to Analyze Common Values of Specific Fields in API Response Data

M66 2025-06-13

In development, processing multidimensional array data returned by an API is a common task. Particularly when we need to extract a specific field from the returned complex data and analyze the most common values of that field, PHP's array_column function is highly efficient and straightforward.

This article uses a typical API response data example to demonstrate how to easily extract a specific field using array_column, and combine it with other PHP functions to count the most frequent values in that field.

1. What is array_column?

array_column is a built-in function introduced in PHP 5.5.0 and later. It allows you to extract the values of a particular column from a multidimensional array and return a one-dimensional array, simplifying the tedious process of manually iterating through the array.

The function prototype is as follows:

array array_column(array $array, string|int|null $column_key, string|int|null $index_key = null)

$array: The input multidimensional array.
$column_key: The key or index of the column to be extracted.
$index_key (optional): The key to be used as the index of the returned array.

2. Typical Scenario: Extracting Fields from API Response Data

Assume we called an API that returned the following format of data:

$apiResponse = [  
    ['id' => 1, 'status' => 'active', 'user' => 'alice'],  
    ['id' => 2, 'status' => 'inactive', 'user' => 'bob'],  
    ['id' => 3, 'status' => 'active', 'user' => 'charlie'],  
    ['id' => 4, 'status' => 'active', 'user' => 'dave'],  
    ['id' => 5, 'status' => 'inactive', 'user' => 'eve'],  
];

We want to analyze the status field and count the occurrences of each status.

3. Using array_column to Extract the Field

Extract the status field:

$statuses = array_column($apiResponse, 'status');

At this point, the content of the $statuses variable is:

['active', 'inactive', 'active', 'active', 'inactive']

4. Counting the Occurrences of Common Values

Use the array_count_values function to count the frequency of each status:

$statusCounts = array_count_values($statuses);

The result is:

[  
    'active' => 3,  
    'inactive' => 2  
]

5. Complete Example Code

Here is the example code combining the API call, replacing the domain with m66.net, extracting the field, and counting the occurrences:

<?php  
// Simulating the API call, replacing the example URL domain with m66.net  
$apiUrl = 'https://api.m66.net/getUserStatuses';  
<p>// Using static data to simulate the API response, actual data can be fetched with file_get_contents or curl<br>
$apiResponse = [<br>
['id' => 1, 'status' => 'active', 'user' => 'alice'],<br>
['id' => 2, 'status' => 'inactive', 'user' => 'bob'],<br>
['id' => 3, 'status' => 'active', 'user' => 'charlie'],<br>
['id' => 4, 'status' => 'active', 'user' => 'dave'],<br>
['id' => 5, 'status' => 'inactive', 'user' => 'eve'],<br>
];</p>
<p>// 1. Extract the status field<br>
$statuses = array_column($apiResponse, 'status');</p>
<p>// 2. Count the occurrences of each status<br>
$statusCounts = array_count_values($statuses);</p>
<p>// Output the result<br>
echo "Status Occurrences Count:\n";<br>
print_r($statusCounts);<br>

After running, the output will be:

Status Occurrences Count:  
Array  
(  
    [active] => 3  
    [inactive] => 2  
)

6. Conclusion

With PHP's built-in function array_column, we can quickly extract a specific field from complex multidimensional arrays, and combine it with functions like array_count_values for statistical analysis, significantly simplifying the data processing workflow.

Whether handling API responses with user information, order statuses, or other business scenarios that require extracting specific fields, array_column is an incredibly useful tool.

Related Tags:
API