Thread: switch()

I would need some help using switch() statement.
We should use switch() statement instead of if() if we have a lot of conditions.
For keeping it simple i only use two conditions here though.

I dont really understand what to put in the place of expression
switch (expression)
{
case valueOne: statement;
break;
case valueTwo: statement;
break;
default: statement;
}

That would be the if() version and i would like that both if() would be true and then to do something after

Code:

if  (str1[pos-3] != ' '  &&  
     str1[pos-2] != 'a' ) 
{
    if  (str1[pos-4] != ' ' && 
         str1[pos-3] != 'a' && 
         str1[pos-2] != 'n' )
        
                    str1[pos] = toupper (str1[pos]);
                          pos += str2.size();
}

Code:

int main (){
   
   ifstream  file1;
   openFile(file1);
   ifstream  file2 ("List of proper nouns.txt");
   ofstream TheCopy;
   TheCopy.open ("Your_Uppercased_Proper_Nouns_Copy.srt",ios::app);
   string str1;
   string str2;
   vector<string> myvector;
   size_t pos = 0;
      
   while (getline(file2, str2)){
           
       myvector.push_back(str2);
   }
       
   while (getline(file1, str1)){
                
         for ( int i = 0; i < myvector.size(); i++){
                    
                while ((pos = str1.find(myvector[i], pos)) != string::npos){
                         
                      if  (str1[pos-3] != ' ' &&  
                           str1[pos-2] != 'a' ){ 
                      
                            if  (str1[pos-4] != ' ' && 
                                 str1[pos-3] != 'a' && 
                                 str1[pos-2] != 'n' )
                                
                                 str1[pos] = toupper (str1[pos]);
                                 pos += str2.size();
                       }              
                }
         }
         TheCopy << str1 << endl;
   }
   file2.close();
   TheCopy.close();
   return 0;
}