Some minor problems with php_PHP tutorial

I have sorted out 2 for everyone to learn from

1. The difference between three equal signs and two equal signs "===" VS "=="

For example Your function will return these situations:
1. Number greater than 0
2. Number less than 0
3. Number equal to 0 (that is, 0)
4. False ( When it fails)
If you want to capture the failure situation at this time, you must use ===, not ==
Because == will not only match the 4th situation, but also the 3rd one situation, because 0 is also false!

Here comes one

$a='2';//Character type 2
$b=2;//Numeric type 2
$a==$b, Yes, both are 2
$a===$b, which is wrong because $a is character type and $b is numeric type. Although the value is the same, the type is different.


2. What are the three angle brackets in PHP? "<<<"