PHP returns an array with key values ​​flipped

php editor Zimo will introduce to you how to use PHP language to realize the flip operation of array key values. By writing simple code, you can quickly swap the keys and values ​​of an array to get a new flipped array. This kind of operation is often used in actual development, and can help us process data more conveniently and improve development efficiency. Next, let’s take a look at the specific implementation method!

PHP key value flip array

Key-value flipping is an operation on an array, which swaps the keys and values ​​in the array to generate a new array with the original key as the value and the original value as the key.

Implementation

In php, you can flip the key value of the array through the following method:

• array_flip() function: The array_flip() function is specially used for key-value flip operations. It receives an array as argument and returns a new array with the keys and values ​​swapped.

$original_array = ["a" => 1, "b" => 2, "c" => 3];
$flipped_array = array_flip($original_array);
print_r($flipped_array);

Output:

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

• Use the array_combine() function: The array_combine() function can combine two arrays into a new array, in which the elements in the first array serve as keys and the elements in the second array serve as value. Key-value flipping can be achieved through a clever combination of two arrays and the array_combine() function.

$keys = array_keys($original_array);
$values ​​= array_values($original_array);
$flipped_array = array_combine($values, $keys);
print_r($flipped_array);

Output:

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

• Use foreach loop: You can use foreach loop to manually exchange the keys and values ​​in the array to achieve key value flipping.

$flipped_array = [];
foreach ($original_array as $key => $value) {
$flipped_array[$value] = $key;
}
print_r($flipped_array);

Output:

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

Precautions

• Keys in the key-flipped array will overwrite any keys with the same value in the original array.
• If the values ​​in the original array are not unique, the array after key value flipping may lose some data.
• When you need to generate a key-flipped array while retaining the original array, it is recommended to use the array_flip() function or array_combine() function because they do not modify the original array.

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