What is the difference between three equal signs (===) and two equal signs (==) in php

Do you know the difference between three equal signs (===) and two equal signs (==) in PHP? This article introduces it in detail for everyone. Friends in need can take a look.

To talk about the difference between three equal signs (===) and two equal signs (==) in PHP, let’s first look at an example: For example, a function will return the following situations: 1. Numbers greater than 0 2. Numbers less than 0 3. A number equal to 0 (that is, 0) 4. False (on failure) When quoting, to capture the failure situation, you must use ===, not == Because == will not only match the 4th case, but also the 3rd case, because 0 is also false!

Three equal signs mean that the types of comparison objects must also be consistent. Two equal signs indicate that the condition is satisfied as long as the values ​​are equal.

Added:

$a='2';//Character type 2 $b=2;//numeric type 2 $a==$b, is correct, both are 2 $a===$b is incorrect because $a is character type and $b is numeric type. Although the value is the same, the type is different. There is also the "0" mentioned in "linvo1986 - Level 6".