(PHP 5, PHP 7)
DOMCharacterData::replaceData — Replace a substring within the DOMCharacterData node
$offset
   , int $count
   , string $data
   )
   Replace count characters starting from position 
   offset with data. 
  
offsetThe offset from which to start replacing.
count
       The number of characters to replace. If the sum of 
       offset and count exceeds
       the length, then all characters to the end of the data are replaced.
      
dataThe string with which the range must be replaced.
No value is returned.
DOM_INDEX_SIZE_ERR
       Raised if offset is negative or greater than the
       number of 16-bit units in data, or if count is 
       negative.