This is the best guide on PHP symbols I’ve every seen. If only something like this existed when I was first learning to code.
Reference:
& =& &= && % !! @ ?: : :: \ -> => ^ >> <<< = == === !== != <> | || ~ + += ++ .= . , $$ ` <?= [] ... **
A list of every symbol in PHP that you’ve ever wanted to know the meaning of.
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