???????????20?????? ??????????

???????????? ???????[ 2012/12/17 10:05:54 ] ????????

????PHP?

????7????????????????????

????If...else????????????????????????????Щ???????飬??????????????и????????п????????д??

1.if ($greeting)
2.{
3.    $post->message = 'Hello';
4.}
5.else
6.{
7.    $post->message = 'Goodbye';
8.}

??????????????????????д???????????????????????????

$post->message = $greeting ? 'Hello' : 'Goodbye';

????8????????????????????ο?????????Inception-Style Nesting??

???????ε???????a?????????????????????????????????????????????????????????????

1.// anti-pattern
2.$error_message = null;
3.if ($this->form_validation->run())
4.{
5.   if ($this->upload->do_upload())
6.   {
7.      $image = $this->upload->get_info();
8.      if ( ! $this->image->create_thumbnail($image['file_name']?? 300?? 150))
9.      {
10.         $error_message = 'There was an error creating the thumbnail.';
11.      }
12.   }
13.   else
14.   {
15.      $error_message = 'There was an error uploading the image.';
16.   }
17.}
18.else
19.{
20.   $error_message = $this->form_validation->error_string();
21.}
22.// Show error messages
23.if ($error_message !== null)
24.{
25.   $this->load->view('form'?? array(
26.      'error' => $error_message??
27.   ));
28.}
29.// Save the page
30.else
31.{
32.   $some_data['image'] = $image['file_name'];
33.   $this->some_model->save($some_data);
34.}

????????????????????????????????????????????????

1.try
2.{
3.   if ( ! $this->form_validation->run())
4.   {
5.      throw new Exception($this->form_validation->error_string());
6.   }
7.   if ( ! $this->upload->do_upload())
8.   {
9.      throw new Exception('There was an error uploading the image.');
10.   }
11.   $image = $this->upload->get_info();
12.   if ( ! $this->image->create_thumbnail($image['file_name']?? 300?? 150))
13.   {
14.      throw new Exception('There was an error creating the thumbnail.');
15.   }
16.}
17.// Show error messages
18.catch (Exception $e)
19.{
20.   $this->load->view('form'?? array(
21.      'error' => $e->getMessage()??
22.   ));
23.   // Stop method execution with return?? or use exit
24.   return;
25.}
26.// Got this far?? must not have any trouble
27.$some_data['image'] = $image['file_name'];
28.$this->some_model->save($some_data);