Program to generate random string in PHP

<?php

// PHP function to print a 
// random string of length n
function RandomStringGenerator($n)
{
    // Variable which store final string
    $generated_string = "";
    
    // Create a string with the help of 
    // small letters, capital letters and
    // digits.
    $domain = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
    
    // Find the length of created string
    $len = strlen($domain);
    
    // Loop to create random string
    for ($i = 0; $i < $n; $i++)
    {
        // Generate a random index to pick
        // characters
        $index = rand(0, $len - 1);
        
        // Concatenating the character 
        // in resultant string
        $generated_string = $generated_string . $domain[$index];
    }
    
    // Return the random generated string
    return $generated_string;
}

// Driver code to test above function
$n = 5;
echo "Random String of length " . $n 
   . " = " . RandomStringGenerator($n);
?>

<?php
function generateRandomString($length) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charactersLength = strlen($characters);
    $randomBytes = random_bytes($length);
    $randomString = '';
    
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[ord($randomBytes[$i]) % $charactersLength];
    }
    
    return $randomString;
}

// Example Usage
echo generateRandomString(5); // Output: e.g., eR3Ds
echo "\n";
echo generateRandomString(10); // Output: e.g., MPRCyBgdcn
?>