Perl regular expressions in PHP implementation to achieve, we want to use the PCRE regular expression functions related, then what are the specific function? Here we introduce to you four, I hope for your help.

Perl regular expressions in PHP functions used in the implementation description:

1, preg_match:

function format:

 
 
   int preg_match (string pattern, string subject,   array   [matches]);   
 
 

This function will use the pattern in the string expression to match, if given the [regs], the string will be recorded in the [regs] [0] in, [regs] [1] on behalf of parentheses “()” Record down the first string, [regs] [2] on behalf of record of the second string, and so on. preg if found in string matching pattern, it will return “true”, otherwise “false”.

2, preg_replace:

function format:

 
 
   mixed preg_replace (mixed pattern, mixed replacement, mixed subject);   
 
 

This function uses the string that matches the expression pattern of all the replaced string expression replacement. If you need replacement parts containing a pattern of characters, you can use “()” to record, just need to use in replacement of “\ \ 1″ to read.

3, preg_split:

function format:

 
 
   array   preg_split (string pattern, string subject, int [limit]);   
 
 

split this function and function the same, the difference with the split can be used only in a simple regular expression to split the string matched, and preg_split using full Perl-compatible regular expression type. The third parameter limit the number of representatives allowed to return eligible value.

4, preg_grep:

function format:

 
 
   array   preg_grep (string patern,   array   input);   
 
 

Basically this function and the preg_match function, but given the array preg_grep can input all the elements match, Returns a new array.

following an example, such as we have to check the Email address in the correct format:

Perl regular expressions in PHP implementation instance:

 
 
     
  function   emailIsRight (  $ email  ) { 
  if   (preg_match (“^[_ \ .0-9a-z  
  0-9a-z] [0-9a- z-] + \.) + [az] {2,3 }$”,  $ email  )) { 
  return   1;  
 }  
  return   0;  
 }  
  if   (emailIsRight (\   ‘y10k@963.net \’)) echo \ ‘right 
 \ ‘ ;  
  if   (! emailIsRight (\   ‘y10k @ fffff \’)) echo \ ‘is not correct 
 \’  ;  
 ?>  
 
 

above program will output “correct
not correct.”

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