How to generate random 4-digit numbers in php without repeating numbers

php generates random 4-digit numbers without repeating the number steps: 1. Define a "generateRandomNumber" function; 2. Use the "range" function to create an array $digits containing 0 to 9; 3. Use "array_rand "The function randomly selects elements in the array; 4. By checking the rules that the first digit cannot be 0 and other digits cannot be repeated, select numbers in a loop until a 4-digit number is generated; 5. Return the generated random number.

The operating environment of this article: Windows 10 system, PHP8.1.3 version, Dell G3 computer.

To generate random 4-digit numbers without repetition, you can use PHP's random number function and array. The following is a possible implementation:

<?php
function generateRandomNumber() {
    $digits = range(0, 9); // 创建一个包含0到9的数组
    $randomNumber = &#39;&#39;;
    // 随机选择数组中的元素，直到生成一个4位数
    while (strlen($randomNumber) < 4) {
        $index = array_rand($digits); // 从数组中随机选择一个索引
        $digit = $digits[$index]; // 获取对应的数字
        // 首位数字不能为0，且其他位数字不能重复
        if (strlen($randomNumber) == 0 && $digit == 0) {
            continue;
        } elseif (strpos($randomNumber, $digit) !== false) {
            continue;
        }
        $randomNumber .= $digit; // 将数字添加到结果中
    }
    return $randomNumber;
}
$number = generateRandomNumber();
echo $number;
?>

This code defines a generateRandomNumber function that uses the range function to create an array containing 0 to 9 and uses the array_rand function to randomly select elements in the array. Then, select numbers in a loop until a 4-digit number is generated by checking the rules that the first digit cannot be 0 and other digits cannot be repeated. Finally, the generated random number is returned.

You can call the generateRandomNumber function to generate a random 4-digit number and output it using the echo statement.

Please note that since random number generation is based on probability, the generated random numbers may repeat. If you need to generate a large number of unique random numbers, you may need to implement a more complex algorithm.

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