concatenate in string php code example

Example 1: php concat

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

echo $c; // hello world

Example 2: php concatenate and add

this is inside for or foreach loop

# For concatenate use           .=
 $var .= 'string';

 # For adding the VALUES use    +=
 $var += 1;