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In PHP, array_reverse() or array_flip() function can be used to achieve array reversal. array_reverse() can reverse the array elements. It will reverse the order of the elements in the original array, create a new array and return it. The syntax is "array_reverse(array,preserve)". array_flip() can reverse the array key-value pairs and exchange the positions of keys and values in the array. The syntax is "array_flip(array)".
The operating environment of this tutorial: windows7 system, PHP8 version, DELL G3 computer
Array inversion can be divided into:
Reverse the position of array elements
Reverse the position of keys and values
In php, array_reverse is available () or array_flip() function to achieve.
Method 1: Use array_reverse() to reverse the position of array elements
array_reverse() function returns an array in the reverse order of elements; It flips the order of elements in the original array, creates a new array and returns it.
Grammar format:
array_reverse(array,preserve)
| Parameters | Description |
|---|---|
| array | Required. Specifies an array. |
| preserve | Optional. Specifies whether to retain the original array key names. If set to TRUE, numeric keys will be preserved. Non-numeric keys are not affected by this setting and will always be retained. Possible values:
|
"Volvo","b"=>"BMW","c"=>"Toyota"); echo "原数组顺序："; var_dump($arr); echo "
数组反转后的顺序："; var_dump(array_reverse($arr)); var_dump(array_reverse($arr,true)); ?>
Method 2: Use array_flip() to reverse the positions of keys and values
array_flip() function can exchange the keys and values in the array11,"bbb"=>22,"ccc"=>33); echo "原数组："; var_dump($arr1); $arr2=array_flip($arr1); echo "反转数组键值对的数组："; var_dump($arr2); ?>
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