php two-dimensional array conversion

In PHP programming, arrays are very commonly used data structures. A two-dimensional array is a special type of array. It contains multiple ordinary arrays. Each array is a row or a column and consists of a set of ordered data. When actually writing code, we may need to convert the two-dimensional array. Therefore, this article will introduce the conversion method of two-dimensional arrays in PHP and give corresponding code examples.

1. Convert a two-dimensional array to a one-dimensional array

Convert a two-dimensional array to a one-dimensional array, that is, summarize all its internal elements into the same array. This can be achieved using the array_merge() function provided in PHP. This function takes two or more arrays as arguments and merges them into a new array. The following is a simple example:

$array = array(
    array('a', 'b'),
    array('c', 'd')
);

$new_array = call_user_func_array('array_merge', $array);

print_r($new_array);

Output result:

Array
(
    [0] => a
    [1] => b
    [2] => c
    [3] => d
)

2. Convert one-dimensional array to two-dimensional array

Convert one-dimensional array For a two-dimensional array, you need to specify the length of each subarray. Since the length of a one-dimensional array may change, we need to first calculate the length of the subarrays in the new array and split the elements in the original array into these subarrays. The following is an example:

$array = array('a', 'b', 'c', 'd', 'e', 'f');
$chunk_size = 2;

$new_array = array_chunk($array, $chunk_size);

print_r($new_array);

Output result:

Array
(
    [0] => Array
        (
            [0] => a
            [1] => b
        )

    [1] => Array
        (
            [0] => c
            [1] => d
        )

    [2] => Array
        (
            [0] => e
            [1] => f
        )

)

3. Exchange the rows and columns of the two-dimensional array

Exchange the rows of the two-dimensional array Exchange with columns, that is, the rows in the original array are used as columns of the new array, and the columns are used as rows of the new array. This process can be implemented using the array_map() function provided in PHP. This function receives one or more arrays as parameters and a callback function that will be used to process each element in the array. Here is an example:

$array = array(
    array('a', 'b', 'c'),
    array('d', 'e', 'f'),
    array('g', 'h', 'i')
);

$new_array = array_map(null, ...$array);

print_r($new_array);

Output result:

Array
(
    [0] => Array
        (
            [0] => a
            [1] => d
            [2] => g
        )

    [1] => Array
        (
            [0] => b
            [1] => e
            [2] => h
        )

    [2] => Array
        (
            [0] => c
            [1] => f
            [2] => i
        )

)

4. Convert one-dimensional array to object array

Convert one-dimensional array to object array , you need to create a new empty object and use each element of the original array as an attribute of the object. The following is an example:

$array = array(
    'name' => 'John',
    'age' => 30,
    'email' => 'john@example.com'
);

$obj = (object) $array;

print_r($obj);

Output result:

stdClass Object
(
    [name] => John
    [age] => 30
    [email] => john@example.com
)

5. Convert object array to one-dimensional array

Convert object array to one-dimensional array , which can be achieved using the get_object_vars() function provided in PHP. This function receives an object as a parameter and returns an associative array containing all properties and property values ​​of this object. The following is an example:

$obj = new stdClass();
$obj->name = 'John';
$obj->age = 30;
$obj->email = 'john@example.com';

$array = get_object_vars($obj);

print_r($array);

Output result:

Array
(
    [name] => John
    [age] => 30
    [email] => john@example.com
)

Summary

In PHP programming, the conversion of two-dimensional arrays is a very practical skill. This article introduces five common conversion methods and gives corresponding code examples. Different conversion methods can meet different needs. Programmers can choose the most suitable conversion method to process two-dimensional arrays based on their actual development scenarios.

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