php unique random number

1you can use rand() function for that in php.
2Example:
3Generate random numbers between 1 to 50
4<?php
5  echo rand(1,50);
6?>

1$uniqueCode = md5(uniqid(rand(), true)); echo $uniqueCode;

1<?php 
2    $random = substr(md5(mt_rand()), 0, 7);
3    echo $random;
4?>

1<?php
2$n=range(11,20);
3shuffle($n);
4for ($x=0; $x< 10; $x++)
5{
6echo $n[$x].' ';
7}
8echo "\n"
9?>
10
11