PHP=symbol writing

The writing of = symbols in programs follows the following rules:
a. On both sides of the = symbol, a space must be left; such as $a = $b, if ($a = = $b), etc.;
b. In a declaration block, or a block that implements the same function, it is required that the = signs be aligned up and down as much as possible. Multiple spaces can be used on the left side to maintain alignment, while one space is required on the right side; as an example:

$testa = $aaa;
$testaa = $bbb;
$testaaa = $ccc;