static public function fromCamel($str) {
      $str[0] = strtolower($str[0]);
      return preg_replace_callback('/([A-Z])/', function($char) {return "_" . strtolower($char[1]);}, $str);
  }
static public function fromCamel($str) {
      $str[0] = strtolower($str[0]);
      return preg_replace_callback('/([A-Z])/', function($char) {return "_" . strtolower($char[1]);}, $str);
  }
static public function fromCamel ( $ str ) { $ str [ 0 ] = strtolower ( $ str [ 0 ] ) ; return preg_replace_callback ( '/([A-Z])/' , function ( $ char ) { return "_" . strtolower ( $ char [ 1 ] ) ; } , $ str ) ; }
Converts camel-case to corresponding underscores.

@param $str

@example helloWorld -> hello_world
@return string
Converts camel - case to corresponding underscores .