随机生成6位数字 php

<?php
function generateRandomNumber($length = 6) {
    $characters = '0123456789';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;
}

$randomNumber = generateRandomNumber();
echo "生成的6位随机数字是: " . $randomNumber;
?>

<?php
function generateRandomNumber($length = 6) {
    $characters = '0123456789';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[mt_rand(0, $charactersLength - 1)];
    }
    return $randomString;
}

$randomNumber = generateRandomNumber();
echo "生成的6位随机数字是: " . $randomNumber;
?>

<?php
function generateUniqueRandomNumber($length = 6) {
    $characters = '0123456789';
    $charactersLength = strlen($characters);
    $randomString = '';
    do {
        $randomString = '';
        for ($i = 0; $i < $length; $i++) {
            $randomString .= $characters[mt_rand(0, $charactersLength - 1)];
        }
    } while (checkIfNumberExists($randomString)); // 假设 checkIfNumberExists 是一个检查数字是否已存在的函数
    return $randomString;
}

$randomNumber = generateUniqueRandomNumber();
echo "生成的唯一6位随机数字是: " . $randomNumber;
?>