How to get the value of a specified column in a two-dimensional array using the array_column function in PHP

In PHP programming, we often need to operate on arrays, including obtaining the value of a specified column. PHP provides a very convenient function - array_column, which can help us quickly obtain the value of a specified column in a two-dimensional array. This article will introduce how to use the array_column function.

Basic usage of array_column function:

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

Parameter description:

$array: The two-dimensional array to be operated on.

$column_key: The index value of the column to be obtained, which can be a string or an integer.

$index_key: Optional parameter, used as the index of the returned array. If this parameter is specified, the returned array will be indexed by the value corresponding to this parameter, otherwise the returned array will be numerically indexed.

Example:

Below we use a specific example to demonstrate how to use the array_column function.

In the following two-dimensional array, we need to obtain two columns of data: name and age of each person.

$people = array(

array('name' => 'Tom', 'age' => 18, 'gender' => 'male'),
array('name' => 'Lucy', 'age' => 20, 'gender' => 'female'),
array('name' => 'Jerry', 'age' => 22, 'gender' => 'male')

);

Get the value of the specified column:

We can get the name and age of each person through the following code , returns a new two-dimensional array $people_info:

$people_info = array_column($people, 'name', 'age');

In the above code, the first parameter $people It is the two-dimensional array that needs to be operated. The second parameter 'name' is the index value of the column that needs to be obtained, and the third parameter 'age' is the index value of the returned array.

Output array $people_info:

Array
(

[18] => Tom
[20] => Lucy
[22] => Jerry

)

We can see that the array $people_info is based on the age of each person Index, with name as value.

Get the values ​​of multiple columns:

If you need to get the values ​​of multiple columns, you can use the following code:

$people_info = array_column($people, null, array('name', 'age'));

In the above code, the first parameter $people is the two-dimensional array that needs to be operated. The second parameter null means to get the values ​​​​of all columns. The third parameter Each parameter array('name', 'age') is the index value of the column that needs to be obtained.

Output array $people_info:

Array
(

[0] => Array
    (
        [name] => Tom
        [age] => 18
        [gender] => male
    )

[1] => Array
    (
        [name] => Lucy
        [age] => 20
        [gender] => female
    )

[2] => Array
    (
        [name] => Jerry
        [age] => 22
        [gender] => male
    )

)

We can see that the array $people_info contains the name of each person , age and gender.

Summary:

The array_column function is a very convenient function in PHP, which can quickly obtain the value of a specified column in a two-dimensional array. After using the array_column function, we can handle array-related operations more efficiently.

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