To disrupt the order of PHP arrays, 1. Use the shuffle() function to randomly disrupt the element order and discard the original key name; 2. If you need to retain the key name, you can use array_rand() to rebuild the array with loop; 3. For multi-dimensional arrays, you can still use shuffle() to process top-level elements, or combine usort() with random comparison functions to implement more complex sorting logic. These methods can be selected and used according to specific needs.
Sometimes you may want to disrupt the order of PHP arrays, such as when making a random recommendation or lottery function. In fact, it is not difficult to implement. PHP has built-in related functions, which can be done by using them directly.
Using the shuffle() function is the easiest way
This is the most common and direct way. shuffle() function randomly disrupts the element order of the array and does not retain the original key name.
$array = [1, 2, 3, 4, 5]; shuffle($array); print_r($array);
After execution, the order of the output arrays will be different each time. Note that this function will modify the original array and return a boolean value (return true for success, false for failure), so if you want to keep the original array, remember to copy a copy first before operation.
If you need to preserve the key name, you can use array_rand() to rebuild it together
If you don't want to lose the original key, or what you need is an array of key-rearranged randomly but still retain the key-value correspondence, shuffle() is not suitable. At this time, you can use array_rand() to extract the random list of keys and then manually reorganize the array:
$array = ['a' => 1, 'b' => 2, 'c' => 3];
$keys = array_rand($array, count($array));
$shuffled = [];
foreach ($keys as $key) {
$shuffled[$key] = $array[$key];
}
print_r($shuffled);This way, the original key can be retained and the effect of randomization of sequence can be achieved.
Multidimensional arrays or other structures can also be flexibly processed
If the array is multidimensional, such as each item is an associative array or object, it does not affect the use of shuffle() . It still works fine, just randomly sorting the top-level elements.
For more complex scenarios, such as if you want to sort "pseudo-randomly" according to a certain field, you can also combine usort() and random comparison functions to implement:
usort($array, function($a, $b) {
return rand(-1, 1);
});Although it is slightly less efficient, it can also achieve its purpose in certain specific situations.
Basically these are the methods. Most of the time in development shuffle() is enough. Other situations can be selected in different ways according to your needs.
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