Why a full stop, “.” and not a plus symbol, “+”, for string concatenation in PHP?

Question

Why did the designers of PHP decide to use a full stop / period / \".\" as the string concatenation operator rather than the more usual plus symbol \"+\" ?

Is there

Answer 1

I am not a PHP expert, but, how else do you do differentiate that last two lines?

$first  = 100;
$second = 20;
$stringresult     = $first . $second; // "10020"
$arithmeticresult = $first + $second; // 120