The Difference Between Null, Empty And Zero-Length Data / Strings:
PHP Comparison Operator Versus Identity Operator

strpos() position of V in Valerie is: 0
strpos() return value of V in Valerie is of type: integer
strpos() comparison operator says V is not in Valerie
strpos() identity operator says V is in Valerie

The Difference Between Null, Empty And Zero-Length Data / Strings

The Difference Between Null, Empty And Zero-Length Data / Strings: PHP Comparison Operator Versus Identity Operator

The Difference Between Null, Empty And Zero-Length Data / Strings:
PHP Comparison Operator Versus Identity Operator