Let’s go with a trivia.
What is the output of
var_dump((bool) "0");
var_dump((bool) "toto");
var_dump((bool) ("0" == "toto"));
You might think like I did
bool(false) bool(true) bool(false)
and you would be wrong. The output is:
bool(false) bool(true) bool(true)
Hold on, what? So if “0” == “toto” is true, then given that “0” is false and “toto” is true, then I get the crazy conclusion that false == true. Woa!
When reading php “empty” documentation, we can confirm that the string “0” is considered empty and hence converts to the boolean false. Then how is “0” == “toto” true? I have no idea.
Of course, if you use the triple equality operator, you get the expected result.
var_dump((bool) ("0" === "toto"));
will return false;
Conclusion: use the triple equality operator as much as you can.
PS.: If anyone knows why this is so, feel free to leave a reply.