????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);
 


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