Error expected unqualified id before public

Contents

• Why Are You Getting the Expected Unqualified Id Error?
  • – Missing or Misplaced Semicolons
  • – Extra or Missing Curly Braces
  • – String Values Without Quotes
• How To Fix the Error?
  • – Get Right With Semicolons
  • – Adjust the Curly Braces To Fix the Expected Unqualified Id Error
  • – Wrap the String Values inside Quotes
• FAQ
  • – What Does a Qualified ID Mean?
  • – What Does the Error: Expected ‘)’ Before ‘;’ Token Inform?
  • – What Do You Mean By Token in C++?
• Conclusion

• Author
• Recent Posts

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• Ubuntu Specialised Support
• Development & Programming
• Programming Talk
• expected unqualified-id before ‘public’

1. expected unqualified-id before ‘public’
   

   Code:

   //bubble.h
   
   #ifndef BUBBLE_H
   #define BUBBLE_H
   
   //#include <iostream>
   //#include <cstdio>
   
   public class bubble{
   
   public:
       bubble();
   
   }
   #endif // BUBBLE_H

   Code:

   //bubble.cpp
   
   #include "bubble.h"
   #include <iostream>
   #include <cstdio>
   
   using namespace std;
   
   void bubble(){
   cout<<"put the data in plz n"<<endl;
   int t [5];
   for (int k=0;k<5;++k){
   scanf("%d", &t[k]);
   cout<<"before: "<<dec<<static_cast<intptr_t>(t[k])<<"n"<<endl;
   }
   for (int i=0;i<5;++i){
       for (int j=0;j<5-i+2;++j){
               if (t[i]>t[i+1]){
               int c = t[i+1];
               t[i+1]=t[i];
               t[i]=c;
       }
           }
       cout<<"after:  "<<dec<<static_cast<intptr_t>(t[i])<<"n"<<endl;
   }
   }
   }

   Code:

   //main.cpp
   
   #include "bubble.h"
   //#include <iostream>
   
   int main()
   {
       cout<<"hello user,I wanna play the game with yan 1. bubblen ";
       int u=0;
       scanf("%d",&u);
       switch(u){
       case 1:
           bubble();
       }
   
       return 0;
   }

   So..As you can see,I have a simple program which provides a user to insert few digits and program will sort it. In main,I`m writing program`s interface. Bubble sort is in another module…
   During comilation, it makes an error named

   Code:

   expected unqualified-id before 'public'

   if I use access specifier for methods (wheter in *.cpp or *.h file)
   and makes another error

   Code:

   new types may not be defined in a return type

   if I don`t.

   whats the problem?
   please help…

   ---

2. Re: expected unqualified-id before ‘public’
   

   Originally Posted by Segaman
   

   Code:

   //bubble.h
   
   #ifndef BUBBLE_H
   #define BUBBLE_H
   
   //#include <iostream>
   //#include <cstdio>
   
   public class bubble{
   
   public:
       bubble();
   
   }
   #endif // BUBBLE_H

   Code:

   //bubble.cpp
   
   #include "bubble.h"
   #include <iostream>
   #include <cstdio>
   
   using namespace std;
   
   void bubble(){
   cout<<"put the data in plz n"<<endl;
   int t [5];
   for (int k=0;k<5;++k){
   scanf("%d", &t[k]);
   cout<<"before: "<<dec<<static_cast<intptr_t>(t[k])<<"n"<<endl;
   }
   for (int i=0;i<5;++i){
       for (int j=0;j<5-i+2;++j){
               if (t[i]>t[i+1]){
               int c = t[i+1];
               t[i+1]=t[i];
               t[i]=c;
       }
           }
       cout<<"after:  "<<dec<<static_cast<intptr_t>(t[i])<<"n"<<endl;
   }
   }
   }

   Code:

   //main.cpp
   
   #include "bubble.h"
   //#include <iostream>
   
   int main()
   {
       cout<<"hello user,I wanna play the game with yan 1. bubblen ";
       int u=0;
       scanf("%d",&u);
       switch(u){
       case 1:
           bubble();
       }
   
       return 0;
   }

   So..As you can see,I have a simple program which provides a user to insert few digits and program will sort it. In main,I`m writing program`s interface. Bubble sort is in another module…
   During comilation, it makes an error named

   Code:

   expected unqualified-id before 'public'

   if I use access specifier for methods (wheter in *.cpp or *.h file)
   and makes another error

   Code:

   new types may not be defined in a return type

   if I don`t.

   whats the problem?
   please help…

   Maybe the compiler gives a file name and a line number, too?

   ---

3. Re: expected unqualified-id before ‘public’
   

   yes,sorry..

   Code:

   expected unqualified-id before 'public'  bubble.h 7

   this line gives an error in both cases

   ---

4. Re: expected unqualified-id before ‘public’
   

   Missing semicolon at the end of class declaration.
   For the bubble cpp file:
   Declaration definition should be like this.

   Code:

   bubble::bubble{//code here}

   aka:

   Code:

   return type CLASS::METHOD(PARAMETERS){FUNCTION BODY}

   And remove that public word before the class keyword in you .h file. It is not necessary and syntactically incorrect.

   I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.
   Freedom is measured in Stallmans.
   Projects: gEcrit

   ---

5. Re: expected unqualified-id before ‘public’
   

   fixed,but got new error

   Code:

    undefined refference to 'bubble::bubble'  main.cpp 13

   intresting that my code has been successfuly compiled in WinXP

   ---

6. Re: expected unqualified-id before ‘public’
   

   Originally Posted by Segaman
   

   fixed,but got new error

   Code:

    undefined refference to 'bubble::bubble'  main.cpp 13

   intresting that my code has been successfuly compiled in WinXP

   I think that the original problem was the word «public» before the class definition. I don’t know what it does in WinXP, but g++ doesn’t like it.

   Apart from that, you don’t actually use the class, just the function bubble. I suppose you will start using the class later.

   A note about error messages: it seems you copied it by hand, since there’s a spelling error in it (I can’t help it — I notice such things). It doesn’t matter this time, but it’s mostly a good idea to copy such messages exactly as they are, with copy/paste, so nothing important gets lost. Sometimes tiny details are important.

   ---

7. Re: expected unqualified-id before ‘public’
   

   damn…its such a strange feeling when you know how to do smth but cant make it work…

   ---

8. Re: expected unqualified-id before ‘public’
   

   1. In ‘bubble.cpp’ you don’t implement your class constructor. (well you try but you’re doing it totally wrong)

   2. In ‘main.cpp’ you try to use the class constructor directly and you dont create a local instance of the class. I am refering to the usage of ‘bubble()’ <—- this is your constructor, you don’t call it directly.

   Take a look in this tutorial page to have some enlightment: http://www.cplusplus.com/doc/tutorial/classes/

   ---

9. Re: expected unqualified-id before ‘public’
   

   UPDATE:

   Code:

   //bubble.h
   
   #ifndef BUBBLE_H
   #define BUBBLE_H
   
   #include <iostream>
   #include <cstdio>
   
   class sort{
   
   public:
       void bubble();
       sort();
       ~sort();
   
   };
   
   #endif // BUBBLE_H

   Code:

   //bubble.cpp
   
   #include "bubble.h"
   
   using namespace std;
   
   
   //sort::sort();
   //sort::~sort();
   
   void bubble(){
       cout<<"put the data in plz n"<<endl;
       int t [5]={0,0,0,0,0};
       for (int k=0;k<5;++k){
           scanf("%d", &t[k]);
           //cout<<"before: "<<dec<<static_cast<intptr_t>(t[k])<<"n"<<endl;
           printf("%dn",t[k]);
       }
       int i=0;
       for (int j=0;j<5-i+1;++j){
           for (i=0;i<4;++i){
               if (t[i]>t[i+1]){
                   int c = t[i+1];
                   t[i+1]=t[i];
                   t[i]=c;
               }
           }
           for (int l=0;l<5;++l){
               printf(" n");
               printf("%dn",t[j]);
           }
           //cout<<"after:  "<<dec<<static_cast<intptr_t>(t[i])<<"n"<<endl;
       }
       int o=0;
       scanf("%d",&o);
   }

   Code:

   //main.cpp
   
   #include "bubble.h"
   //#include <iostream>
   
   using namespace std;
   
   int main()
   {
       cout<<"hello user,I wanna play the game with yan 1. bubblen ";
       int u=0;
       scanf("%d",&u);
       switch(u){
       case 1:
           sort *s = new sort();
           s->bubble();
       }
   
       return 0;
   }

   Yet again,I`m geting these errors:

   Code:

    undefined refference to sort::sort() in main.cpp 13
     undefined refference to sort::bubble() in main.cpp 14
     collect2:ld returned 1 exit status

   ---

10. Re: expected unqualified-id before ‘public’
    

    Originally Posted by Segaman
    

    UPDATE:

    Code:

    //bubble.h
    
    #ifndef BUBBLE_H
    #define BUBBLE_H
    
    #include <iostream>
    #include <cstdio>
    
    class sort{
    
    public:
        void bubble();
        sort();
        ~sort();
    
    };
    
    #endif // BUBBLE_H

    Code:

    //bubble.cpp
    
    #include "bubble.h"
    
    using namespace std;
    
    
    //sort::sort();
    //sort::~sort();
    
    void bubble(){
        cout<<"put the data in plz n"<<endl;
        int t [5]={0,0,0,0,0};
        for (int k=0;k<5;++k){
            scanf("%d", &t[k]);
            //cout<<"before: "<<dec<<static_cast<intptr_t>(t[k])<<"n"<<endl;
            printf("%dn",t[k]);
        }
        int i=0;
        for (int j=0;j<5-i+1;++j){
            for (i=0;i<4;++i){
                if (t[i]>t[i+1]){
                    int c = t[i+1];
                    t[i+1]=t[i];
                    t[i]=c;
                }
            }
            for (int l=0;l<5;++l){
                printf(" n");
                printf("%dn",t[j]);
            }
            //cout<<"after:  "<<dec<<static_cast<intptr_t>(t[i])<<"n"<<endl;
        }
        int o=0;
        scanf("%d",&o);
    }

    Code:

    //main.cpp
    
    #include "bubble.h"
    //#include <iostream>
    
    using namespace std;
    
    int main()
    {
        cout<<"hello user,I wanna play the game with yan 1. bubblen ";
        int u=0;
        scanf("%d",&u);
        switch(u){
        case 1:
            sort *s = new sort();
            s->bubble();
        }
    
        return 0;
    }

    Yet again,I`m geting these errors:

    Code:

     undefined refference to sort::sort() in main.cpp 13
      undefined refference to sort::bubble() in main.cpp 14
      collect2:ld returned 1 exit status

    You have defined a plain function ‘bubble’, but not sort::bubble. How do you expect the compiler to know that you want ‘bubble’ to be called when you do s->bubble()?

    Nor have you defined the constructor for ‘sort’, that is, sort::sort. You can do it inline with just {} if you don’t need it to do anything.

    ---

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