how to create unique Id random php code example

Example 1: php unique random number

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

Example 2: generate unique random number php

<?php
$n=range(11,20);
shuffle($n);
for ($x=0; $x< 10; $x++)
{
echo $n[$x].' ';
}
echo "\n"
?>