Php character inversion

: This article mainly introduces php character inversion. if you are interested in the PHP Tutorial, you can refer to it. 1. use php built-in functions for implementation
Test Code

  '; $ Str = 'Hello World! Hello world! '; $ Res = reverse ($ str); echo $ res; // custom function functionreverse ($ str) {$ len = mb_strlen ($ str, 'utf-8'); for ($ I = 0; $ I <$ len; $ I ++) {$ arr [] = mb_substr ($ str, $ I, 1, "UTF-8");} return implode ("", array_reverse ($ arr) ;}?>

Running result
! DlroW olleH!
Hello! DlroW olleH

2. c language implementation

#Include 
  
   
#
   Include
   
    
Char * str = "Hello World! Hello world! "; Int main () {int I = strlen (str)-1; while (I> = 0) {if (str [I] <0) {printf ("% c \ n", str [i-2], str [i-1], str [I]); I = I-2 ;} else {printf ("% c \ n", str [I]);} I --;} return0 ;}
   
  

'). AddClass ('pre-numbering '). hide (); $ (this ). addClass ('Has-numbering '). parent (). append ($ numbering); for (I = 1; I <= lines; I ++) {$ numbering. append ($ ('

'). Text (I) ;}; $ numbering. fadeIn (1700) ;}) ;}; script

The above introduces php character inversion, including the include content, and hopes to help friends who are interested in PHP tutorials.