concatinate two variable in php code example

Example 1: php concat

$a = "hello";
$b = "world";
$c = $a . " " . $b;

echo $c; // hello world

Example 2: php append string

<?php
$a = "Hello ";
$b = $a . "World!"; // now $b contains "Hello World!"

$a = "Hello ";
$a .= "World!";     // now $a contains "Hello World!"
?>