How to reassemble a two-dimensional array into another array in php

In PHP, a two-dimensional array refers to an array containing one or more arrays. Two-dimensional arrays are created using nested arrays. Often, programmers need to handle large amounts of data in complex applications. In this case, 2D arrays can act like a powerful tool for storing, organizing, and manipulating data.

In this article, we will discuss how to reassemble a two-dimensional array into a new array.

1. Initial array

Let us first define a two-dimensional array containing some student information, as shown below:

$students = array(
    array('name' => 'John', 'age' => 21, 'gender' => 'Male'),
    array('name' => 'Jane', 'age' => 19, 'gender' => 'Female'),
    array('name' => 'Jim', 'age' => 24, 'gender' => 'Male'),
    array('name' => 'Jenny', 'age' => 20, 'gender' => 'Female')
);

This two-dimensional array contains Four internal arrays, each containing three key-value pairs.

2. Reassemble the array

Now we want to reassemble this 2D array into a one-bit array of key–value pairs, the values ​​will be for each student The name,key will be the gender of each student.

To accomplish this task, we need to use a foreach loop to iterate through the initial array and add the "name" element of each inner array to the new array.

$new_array = array();
foreach ($students as $student) {
    $new_array[$student['gender']][] = $student['name'];
}

Inside this loop, we first retrieve the gender and name of each student by accessing the $student array defined in the first foreach statement. We then use another foreach statement to create a list of elements in the new array. This list of elements consists of a key-value pair, where the key is the student's gender and the value is an array containing the names of all students of the same gender. Each element of this array consists of a name, which is added to the array corresponding to the key through the [] operator.

We can use the following command to output a new array:

print_r($new_array);

The output will look like this:

Array
(
    [Male] => Array
        (
            [0] => John
            [1] => Jim
        )

    [Female] => Array
        (
            [0] => Jane
            [1] => Jenny
        ) 
)

This new array now has the gender of each student as the key and is Create an array of names for each gender. The result is a simplified, more readable and manipulable data structure.

3. Summary

In this article, we introduced how to reassemble a two-dimensional array into a one-dimensional array of key-value pairs. We went through the initial array using a foreach loop and created a new array with the students' names. This new array is keyed by the student's gender and creates an array of names for each gender. This process can significantly simplify the data structure, making it easier to read, manage, and process.

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