A brief analysis of the difference between three equal signs (===) and two equal signs (==) in PHP_PHP Tutorial

Let’s give an example first:
For example, a function of yours will return these situations:
1. Numbers greater than 0
2. Numbers less than 0
3. A number equal to 0 (that is, 0)
4. False (when failure)
At this time, if you want to capture the failure situation, you must use === instead of Use ==
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.

Let’s add some more:
$a='2';//Character type 2
$b=2;//Numeric type 2
$a==$b , is correct, both are 2
$a===$b, which 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".

http://www.bkjia.com/PHPjc/328150.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/328150.htmlTechArticleFirst give an example: For example, a function of yours will return these situations: 1. Numbers greater than 0 2. Numbers less than 0 3. Numbers equal to 0 (that is, 0) 4. False (when failed) At this time, if you...