How to recall array with key value in php

In PHP programming, flashback array key values ​​are a common operation. Normally, we need to arrange the elements in the array in reverse order and retain the original key values ​​of the array. In this article, we will explain how to implement such functionality using PHP code.

Implementation method

PHP provides a variety of methods to recall arrays, including using functions and loops. We can choose the method that best suits us to accomplish this task. The following is one of the simple methods:

function reverse_array($array) {
  $keys = array_keys($array);
  $values = array_reverse($array);
  return array_combine($keys, $values);
}

This function will first obtain the key values ​​​​($keys) of the array, then arrange the array backwards and assign the result to the new array ($values). Finally, use the array_combine() function to combine the keys of the original array with the values ​​of the new array to obtain a new array of flashback arrays with key values. The return result of this function is an array with key values ​​in the flashback array.

Example

The following is a sample code that uses the above function to flash back an array with key values:

// 定义原始数组
$array = array('a' => 'apple', 'b' => 'banana', 'c' => 'cherry');
print_r($array);

// 倒叙数组，并且保留键值
$reversed_array = reverse_array($array);
print_r($reversed_array);

The output of this sample code is as follows:

Array
(
    [a] => apple
    [b] => banana
    [c] => cherry
)
Array
(
    [c] => cherry
    [b] => banana
    [a] => apple
)

From It can be seen from the output that the function successfully arranged the original array backwards and retained the key values ​​of the original array.

Extension

In addition to the above methods, you can also use other functions provided by PHP to implement flashback array operations. Here is another example using PHP's array_reverse() function and a foreach loop to implement a flashback array with key values:

function reverse_array2($array) {
  return array_reverse($array, true);
}

// 定义原始数组
$array = array('a' => 'apple', 'b' => 'banana', 'c' => 'cherry');
print_r($array);

// 倒叙数组，并且保留键值
$reversed_array = reverse_array2($array);
print_r($reversed_array);

The output is the same as the previous code.

Conclusion

PHP provides a variety of methods to implement key-value operations on flashback arrays. By using the above function, we can very easily arrange an array in reverse order and retain the key values ​​​​of the original array. In actual projects, this skill can help us better complete some tasks related to data sorting.

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