strcspn
  Find length of initial segment not matching mask
  
 
 
  Description
  
   int strcspn(
    string $string,
    string $characters,
    int $offset = 0,
    intnull $length = null
)
  
  
   If offset and length
   are omitted, then all of string will be
   examined. If they are included, then the effect will be the same as
   calling strcspn(substr($string, $offset, $length),
   $characters) (see substr
   for more information).
  
  
 
 
  Parameters
  
   
    
     - 
string
- 
      
       The string to examine.
       
- 
characters
- 
      
       The string containing every disallowed character.
       
- 
offset
- 
      
       The position in stringto
       start searching.
 
       If offsetis given and is non-negative,
       then strcspn will begin
       examiningstringat
       theoffset'th position. For instance, in
       the string 'abcdef', the character at
       position0is 'a', the
       character at position2is
       'c', and so forth.
 
       If offsetis given and is negative,
       then strcspn will begin
       examiningstringat
       theoffset'th position from the end
       ofstring.
 
- 
length
- 
      
       The length of the segment from stringto examine.
 
       If lengthis given and is non-negative,
       thenstringwill be examined
       forlengthcharacters after the starting
       position.
 
       If lengthis given and is negative,
       thenstringwill be examined from the
       starting position up tolengthcharacters from the end ofstring.
 
 
 
 
  Return Values
  
   Returns the length of the initial segment of string
   which consists entirely of characters not in characters.
  
  Note: 
   
    When a offset parameter is set, the returned length
    is counted starting from this position, not from the beginning of
    string.
   
  
  
 
 
  Examples
  
   Example #1 strcspn example
   
<?php
$a = strcspn('banana', 'a');
$b = strcspn('banana', 'abcd');
$c = strcspn('banana', 'z');
$d = strcspn('abcdhelloabcd', 'a', -9);
$e = strcspn('abcdhelloabcd', 'a', -9, -5);
var_dump($a);
var_dump($b);
var_dump($c);
var_dump($d);
var_dump($e);
?>
 
   The above example will output:
int(1)
int(0)
int(6)
int(5)
int(4)
 
   
  
 
 
  Notes
  Note: This function is
binary-safe.