A brief analysis of the difference between three equals (= = =) and two equal sign (= =) in PHP _php skill

Let me give you an example:
For example, you can return a function in these situations:
1, the number greater than 0
2, less than 0 of the number
3, equal to 0 of the number (that is, 0)
4, False (when failed)
If you want to catch failure, you must use = = =
because = = except will match the 4th case, will also match the 3rd case, because 0 is also false!

The three equals sign represents the same type of comparison object. A two equal sign means that the condition is satisfied as long as the value is equal.

To add some more:
$a = ' 2 ';//character Type 2
$b =2;//Value type 2
$a = = $b, it's right, it's all 2.
$a = = = $b, is not correct, because $a is a character $b is a numeric type, the value is the same, but the type is different.
There is "linvo1986-level six" said the kind of "0".