CODEWITHSUNDEEP
phprandomnumbers
Zenel Shabani
Zenel Shabani

Reputation: 95

short php code for random number string, 5 chars

I'm having a problem, im trying to generate a 5 or 7 characters long number code with php, but the following code does include letters, i only need numbers, thanks in advance

$newgid = substr(md5(microtime()),rand(0,9),5);

Upvotes: 1

Views: 15776

Answers (7)

person0
person0

Reputation: 1388

To future readers who come across this, I would recommend something like the following:

function generateNumericString(INT $len, STRING $str = '') {
    if (strlen($str) < $len) {
        return generateNumericString($len, $str . random_int(0, 9));
    }
    return $str;
}

Rather than using a loop, the function above uses recursion; it calls itself continuously, adding a single digit to the string, until the string length reaches the specified value. Anywhere and anytime you want you can generate a string of any length (i.e. 5) simply by calling:

generateNumericString(5);

Additionally, this method allows for the first digit in the sequence to include 0.

Although I prefer the first method, if you know you will absolutely never need more than 5 numbers in the string you can technically achieve the same thing with:

$n = substr(random_int(100000, 199999), 1);

This generates a 6 digit integer, then casts it as a string and returns everything after the first digit. Removing the first digit preserves 0 as a possible first character.

EDIT: random_int() is used in place of other methods to ensure generated numbers are cryptographically secure.

Upvotes: 1

CompuSolver
CompuSolver

Reputation: 49

function createPin($len){
    $maxNbrStr = str_repeat('9',$len);
    $maxNbr = intval($maxNbrStr);
    $n = mt_rand(0, $maxNbr);
    $pin = str_pad($n, $len, "0", STR_PAD_LEFT);
    return $pin;
}

Here's a short & sweet function that will produce a string of numbers at the desired length.

Upvotes: 1

user1252065
user1252065

Reputation:

If you don't mind that the numbers start from 10000 instead of zero, this is the shortest way: 

mt_rand(10000, 99999)

Upvotes: 1

Prasannjit
Prasannjit

Reputation: 795

 function randomPrefix($length=5) {       
        $random = "";
        srand((double) microtime() * 1000000);
        $data = "0123456789";
       // $data = "A0B1C2DE3FG4HIJ5KLM6NOP7QR8ST9UVW0XYZ";
        for ($i = 0; $i < $length; $i++) {
            $random .= substr($data, (rand() % (strlen($data))), 1);
        }

        return $random;
    }

Upvotes: 1

Amal Murali
Amal Murali

Reputation: 76646

I'd simply use mt_rand() as follows:

<?php
$a = '';
for ($i = 0; $i<7; $i++) 
{
    $a .= mt_rand(0,9);
}
echo $a;
?>

Demo!

Upvotes: 6

Fluffeh
Fluffeh

Reputation: 33512

You can use the following to generate a 5 digit code quite easily, and I am sure you can work out from here how to make it 7 digits long.

$string='';
for($i=0;$i<5;$i++)
{
    $string.=rand(0,9);
}
echo $string;

Upvotes: 1

Voitcus
Voitcus

Reputation: 4446

I would use rand() to generate number between 0 and 99999 and treat it as string.

$newgid = sprintf('%05d', rand(0, 99999));

Upvotes: 5

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