How to modify and add php array

In development, PHP array is an essential data type. As a very flexible data type, PHP arrays are often used to store and manipulate large amounts of data.

However, in actual application, we often encounter situations where we need to modify and add arrays. This article will introduce the modification and addition operations of PHP arrays.

1. Add Elements

Adding elements to a PHP array is very simple. We can use array subscripts to directly add a new element to the array. For example:

$student = array('Tom', 'Jerry', 'John', 'Lucy');
$student[4] = 'Mike';

The above code can add a student named Mike to the array $student. When outputting the array $student, we can get the following output:

Array
(
    [0] => Tom
    [1] => Jerry
    [2] => John
    [3] => Lucy
    [4] => Mike
)

2. Modify elements

Modifying elements in a PHP array is also very simple. We also use array subscripts to directly update the elements that need to be modified. For example:

$student = array('Tom', 'Jerry', 'John', 'Lucy');
$student[2] = 'David';

The above code changes the John element in the array $student to David. When outputting the array $student, we can get the following output:

Array
(
    [0] => Tom
    [1] => Jerry
    [2] => David
    [3] => Lucy
)

3. Deleting elements

Deleting elements in a PHP array is also very simple. We can use the unset function of PHP array to directly delete elements in the array. For example:

$student = array('Tom', 'Jerry', 'John', 'Lucy');
unset($student[2]);

The above code deletes the John element in the array $student. When outputting the array $student, we can get the following output:

Array
(
    [0] => Tom
    [1] => Jerry
    [2] => Lucy
)

It should be noted that the unset function only deletes the elements in the array and does not re-index the array. Therefore, you need to pay attention to the change of array index when using the unset function.

4. Use the array_splice function to add and delete elements

In addition to the above methods of adding and deleting elements, you can also use the array_splice function of the PHP array to add and delete array elements. operate. For example:

$student = array('Tom', 'Jerry', 'John', 'Lucy');
array_splice($student, 2, 0, array('Mike'));

The above code adds the student named Mike to the third position of the array $student. When outputting the array $student, we can get the following output:

Array
(
    [0] => Tom
    [1] => Jerry
    [2] => Mike
    [3] => John
    [4] => Lucy
)

We can also use the array_splice function to delete elements in the array. For example:

$student = array('Tom', 'Jerry', 'John', 'Lucy');
array_splice($student, 2, 1);

The above code deletes the John element in the array $student. When outputting the array $student, we can get the following output:

Array
(
    [0] => Tom
    [1] => Jerry
    [2] => Lucy
)

Summary

This article introduces the modification and addition operations of PHP arrays, including adding and modifying using array subscripts elements, remove elements using the unset function, and add and remove elements using the array_splice function. During the application process, we can choose different methods to perform array operations according to specific situations to achieve better results.

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