php - 多次调用一个方法，有没有更有效的方法呢？

Question

我有一个用户注册脚本。在一个阶段我调用一个方法三次。一旦检查该方法是否返回 true，否则如果没有，它是否返回一个字符串(包含错误消息)，如果它确实获取返回的字符串并将其放在一个变量中。

这样做是否更有效率，我只需要调用该方法一次？但仍能得到我需要的所有答案？

代码如下:

//check thumbnail is present and good
            if($register->checkThumb()){
                //send image to permanent image directory
                $register->moveUploadedImage();

                //if the thumbnail failed validation put the error message in variable
            }else if(is_string($register->checkThumb())){
                $message = $register->checkThumb();

            }

Answer 1

    $thumb = $register->checkThumb(); //call method once and save in variable
   /* using just if($thumb) would return always true, because 
      the function may returns an errormessage on failure 
      which is ja string, which is not empty, not 0, not false == true */
    if($thumb === true){
      //send image to permanent image directory
      $register->moveUploadedImage();
    }else{ //so then it's enough to ask for error this way
      $message = $thumb;
    }