PHP Random String And Number Generation Functions

PHP provides built-in functions to generate random strings and numbers for various use cases, such as creating unique identifiers, security tokens, or random values for testing. Below, you will find ready to use PHP functions that generate random strings, numbers, and special character combinations.

These PHP functions provide quick and flexible ways to generate random strings and numbers. You can modify them based on your project needs, such as adjusting the character set, range, or length. Copy and use them in your PHP applications for secure and efficient randomization.

Contents

Random Strings
Random Numbers
Random Number In Range
Random Mixed Strings With Special Characters
Random Alphanumeric String
Cryptographically Secure Random String
UUID String
Random Floating-Point Number
Random Date Between Two Given Dates
Random Number Without Leading Zeros

PHP Function to Generate Random Strings

Generating random strings is useful for unique IDs, passwords, and security tokens. The following PHP function creates a random string using a mix of uppercase and lowercase letters:

JavaScript

<?php
function generateRandomString($length = 10) {
    $characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;
}

// usage
echo generateRandomString(12); // Output: AbcDefGhIjKl

PHP Function to Generate Random Numbers

This function generates a random numbers:

JavaScript

<?php
function generateRandomNumbers($length = 10) {
    $number = '';
    for ($i = 0; $i < $length; $i++) {
        $number .= random_int(0, 9);
    }
    return $number;
}

// usage
echo generateRandomNumbers();   // Output: 5682156254
echo generateRandomNumbers(5);  // Output: 015687

PHP Generate a Random Number Within a Specific Range

This function generates a random number Within a Specific Range. For cryptographically secure random numbers, use random_int():

JavaScript

<?php
function getRandomNumberInRange($min = 1, $max = 100) {
    return random_int($min, $max);
}

// usage
echo getRandomNumberInRange(10, 100); // Output: 56
echo getRandomNumberInRange(1, 10);   // Output: 4

PHP Generate a Random String with Letters, Numbers, and Special Characters

For stronger security, this function includes letters, numbers, and special characters:

JavaScript

<?php
function generateMixedRandomString($length = 10) {
    $characters = 'abcdefghijklmnopqrstuvwxyz'; // lowercase
    $characters .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; // uppercase
    $characters .= '0123456789'; // numbers
    $characters .= '~!@#$%^&*()_+}{></[]|-,:;\'".?'; // special characters
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;
}

// usage
echo generateMixedRandomString();     // Output: ahGH5+*6(f
echo generateMixedRandomString(12);   // Output: 5+*G^%$gdkgA

PHP Generate a Random Alphanumeric String (Letters + Numbers Only)

A function that generates a random string with only letters and numbers, commonly used for tokens or verification codes.

JavaScript

<?php
function generateAlphanumericString($length = 12) {
    $characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;
}

// usage
echo generateAlphanumericString();     // Output: 2B3x9tLP2L
echo generateAlphanumericString(10);   // Output: 5gdkDki

PHP Generate a Cryptographically Secure Random String

Uses random_bytes() and bin2hex() for high-security applications like API keys or authentication tokens.

JavaScript

<?php
function generateSecureRandomString($length = 16) {
    return bin2hex(random_bytes($length / 2));
}

echo generateSecureRandomString(16); // Output: 4f3d2e7c1a5b9d8f

PHP Generate a UUID (Universally Unique Identifier - Version 4)

This function creates a random UUID following RFC 4122 standards.

JavaScript

<?php
function generateUUIDv4() {
    $data = random_bytes(16);
    $data[6] = chr(ord($data[6]) & 0x0f | 0x40); // Set version to 4
    $data[8] = chr(ord($data[8]) & 0x3f | 0x80); // Set variant to 10x
    return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
}

echo generateUUIDv4(); // Output: e9b1a12b-45c6-4a27-b87a-1f23d90d2b87

PHP Generate a Random Floating-Point Number

Generates a random floating point number between specified minimum and maximum values with the specified decimal precision. Useful for randomizing decimal values.

JavaScript

<?php
function generateRandomFloat(float $min = 0, float $max = 1, int $precision = 2): float {
    if ($min >= $max) {
        throw new InvalidArgumentException('Minimum value must be less than maximum value.');
    }
    if ($precision < 0) {
        throw new InvalidArgumentException('Precision must be a non-negative integer.');
    }

    $scale = pow(10, $precision);
    $randomFloat = random_int((int) ($min * $scale), (int) ($max * $scale)) / $scale;

    return round($randomFloat, $precision);
}

// Example usage:
echo generateRandomFloat(1.5, 9.9, 3); // Output: 3.472

PHP Generate a Random Date Between Two Given Dates

Generate a random date between two dates. Useful for generating random timestamps.

PHP

<?php
function generateRandomDate(string $startDate, string $endDate, string $format = 'Y-m-d H:i:s'): string {
    try {
        $start = new DateTime($startDate);
        $end = new DateTime($endDate);
    } catch (Exception $e) {
        throw new InvalidArgumentException('Invalid date format provided.');
    }

    if ($start >= $end) {
        throw new InvalidArgumentException('Start date must be earlier than end date.');
    }

    $randomTimestamp = random_int($start->getTimestamp(), $end->getTimestamp());

    return (new DateTime())->setTimestamp($randomTimestamp)->format($format);
}

// Example usage:
echo generateRandomDate('2023-01-01', '2023-12-31'); // Output: 2023-06-15 14:23:45

PHP Generate a Random Number Without Leading Zeros

Generates a random number of specified length without leading zeros. This ensures that the generated number does not start with zero:

PHP

<?php
function generateRandomNumberWithoutLeadingZeros(int $length = 6): string {
    if ($length < 1) {
        throw new InvalidArgumentException('Length must be at least 1.');
    }

    $digits = '123456789'; // First digit must be non-zero
    $remainingDigits = '0123456789'; // Remaining digits can be anything

    $randomNumber = $digits[random_int(0, 8)]; // First digit (1-9)
    for ($i = 1; $i < $length; $i++) {
        $randomNumber .= $remainingDigits[random_int(0, 9)];
    }

    return $randomNumber;
}

// Example usage:
echo generateRandomNumberWithoutLeadingZeros(6); // Output: 589473

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