PHP magic constant

PHP magic constant & lt ;? Php & nbsp; ***** & nbsp; & nbsp; public welfare PHP Lecture Hall & nbsp; altar: & nbsp; www. zixue. it & nbsp; Micro & nbsp; blog: & nbsp; weibo. comyshba & nbsp; YY Channel: & nbsp; 8835 PHP magic constant

2. /****
3. Yan 18 public welfare PHP Lecture Hall
5. Discussion: http://www.zixue.it
6. Micro Bo: http://weibo.com/Yshiba
7. YY Channel: 88354001
8. ****/
11. /***
12. === Note ====
13. Magic constant
15. 1: The value cannot be manually modified, so it is called a constant.
16. 2: But the value changes with the environment, so it is called Magic
18. --- Magic constant
19. _ FILE _ return the path of the current FILE.
20. Used to calculate the root directory of a website in framework development or website initialization scripts
22. _ LINE _ returns the current row number.
23. In the framework, it can be used to record error information during debugging.
27. _ CLASS _ returns the current CLASS name
29. _ METHOD _ returns the current METHOD name.
30. ***/
33. Echo 'the currently running is ',__ FILE __, 'file ','
    ';
35. Echo 'current in ',__ DIR __,' Directory
    ';
37. Echo 'Hi, I am at ',__ LINE __,'
    ';
38. Echo 'hello, I am at ',__ LINE __,'
    ';
39. Echo 'Hehe, I am at ',__ LINE __,'
    ';
42. Class Human {
43. Public static function t (){
44. Echo 'You are running ',__ CLASS __,' CLASS
    ';
45. Echo ',__ METHOD __, 'method ';
46. }
47. }
49. Human: t ();