How to randomly remove one or more cells from an array in PHP

php Xiaobian Yuzai will introduce to you how to randomly remove one or more units from an array. In PHP, you can use the array_rand() function to achieve this function. This function can randomly select one or more keys from the array, and returns the key name instead of the value. The corresponding value can be obtained through the returned key name. Through the array_rand() function, you can easily implement the operation of randomly removing one or more units from an array, providing more possibilities for your development work.

How to randomly remove one or more cells from an array

Array is an ordered collection used in php to store data. They consist of a collection of key-value pairs, where the key is a unique identifier and the value is the stored data. Randomly removing one or more cells from an array is a common operation, and there are several ways to do it.

Single element:

1. mt_rand() function:

$array = [1, 2, 3, 4, 5];
$random_index = mt_rand(0, count($array) - 1);
$random_element = $array[$random_index];

2. array_rand() function:

$array = [1, 2, 3, 4, 5];
$random_key = array_rand($array);
$random_element = $array[$random_key];

Multiple elements:

1. array_slice() function:

$array = [1, 2, 3, 4, 5];
$num_elements = 3; //The number of elements randomly taken out
$random_elements = array_slice($array, 0, $num_elements, true);

2. shuffle() function and array_slice() function:

$array = [1, 2, 3, 4, 5];
shuffle($array); //shuffle the order of array elements
$num_elements = 3; //The number of elements randomly taken out
$random_elements = array_slice($array, 0, $num_elements);

3. Self-implemented function:

function random_elements($array, $num_elements) {
$keys = array_rand($array, $num_elements);
$random_elements = array();
foreach ($keys as $key) {
$random_elements[] = $array[$key];
}
return $random_elements;
}

Efficiency considerations:

• For smaller arrays, the mt_rand() and array_rand() functions are more efficient.
• For larger arrays, the array_slice() and shuffle() functions are more efficient because they avoid traversing the entire array.
• If you need to randomly remove elements from a scrambled array, the array_slice() function is the most efficient choice.

Additional tips:

• mt_srand() The function can set the seed value of the random number generator to ensure that the same result can be obtained every time it is executed.
• array_values() The function can convert an associative array into a new array containing only values, making it easier to randomly remove elements from the array.

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