PHP shuffles array, retaining key names

PHP editor Xinyi introduces you to an interesting array operation method-shuffle the array and retain the key names. In PHP, random arrangement of array elements can be easily achieved through the shuffle function, but the indexes will be reassigned. If you want to retain the original key names, you can first use the array_keys function to obtain the key name array, then scramble it together with the value array, and finally recombine it into a new array through the array_combine function. In this way, you can achieve random arrangement of array elements while retaining the key names!

PHP shuffle the array and keep the key names

In php, use the shuffle() function to shuffle the order of the array, but the key names will not be preserved. To preserve key names, you can use the following method:

Method 1: Use array_rand()

$array = ["a" => 1, "b" => 2, "c" => 3];

$keys = array_rand($array);
$shuffled_array = [];

foreach ($keys as $key) {
$shuffled_array[$key] = $array[$key];
}

Method 2: Use mt_rand()

$array = ["a" => 1, "b" => 2, "c" => 3];

$keys = array_keys($array);
shuffle($keys);

$shuffled_array = [];

foreach ($keys as $key) {
$shuffled_array[$key] = $array[$key];
}

Method 3: Using third-party libraries

Third-party libraries, such as ArrayLib, provide a more convenient way to shuffle arrays and retain key names:

use ArrayLibArrays;

$array = ["a" => 1, "b" => 2, "c" => 3];

$shuffled_array = Arrays::shuffle($array);

Performance comparison

There are differences in the performance of these three methods:

• array_rand() Performs best with small arrays, but is less efficient with large arrays.
• mt_rand() Performs well across all array sizes.
• Third-party libraries generally perform better than native PHP functions.

scenes to be used

Disrupting the array and retaining key names is useful in the following scenarios:

• When you need to disrupt the order of elements in an array while still needing to access the key of each element.
• When you need to generate a random playlist or other ordered itemlist.
• When you need to randomly sample the data in the array.

Precautions

• array_rand() and mt_rand() return a key, not a value. Need to use $array[$key] to get the value.
• Third-party libraries may need to be installed before they can be used.
• Make sure to copy the array before shuffling it to avoid modifying the original array.

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