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? "<<<"

Copy code The code is as follows:

$somevar = <<put your code or words here
someword;

Here is the code snippet. One benefit of using code snippets in PHP is that when you need to output a piece of code (which can include multiple lines), the code snippet can maintain a more logical form. Often used to insert HTML code.

Note that someword is any character and represents a mark. <<
can be used to include both single quotes and double quotes in assignments. Well, there are many such in pw

http://www.bkjia.com/PHPjc/322097.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/322097.htmlTechArticleI compiled 2 for everyone to learn: 1. The difference between three equal signs and two equal signs"== =" VS "==" For example, your function will return the following situations: 1. A number greater than 0 2, a number less than 0 3, etc...