1$arraysAreEqual = ($a == $b); // TRUE if $a and $b have the same key/value pairs.
2$arraysAreEqual = ($a === $b); // TRUE if $a and $b have the same key/value pairs
3 // in the same order and of the same types.
4$arraysAreEqual = (array_diff($a, $b)==[] && array_diff($a, $b) == []);