help i cant get it working

i am new with c. i was using c++ before this. i dont get it why i cant get it to work with so many error. can someone show me the correct way.
i was wondering which is the best function to use in order to prom a error message when an invalid character is entered then go back to the scanf function to enter again.
thanks

One thing I noticed when opening in a syntax-highlighting text editor (SciTE)...some of your printfs have extra quotes.

Quote:

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Originally Posted by rags_to_riches

One thing I noticed when opening in a syntax-highlighting text editor (SciTE)...some of your printfs have extra quotes.

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He is right. Also i think you like to do

Code:

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    do
    {
      printf("enter option here: ");
      scanf("%d",&option);
      switch ( option )

---

instead of

Code:

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printf("enter option here: ");
        scanf("%d",&option);
        do
        {

        switch ( option )

---

When I compile your program using VC++ 6.0, I get 102 errors, not to mention the warnings. Your #define statements won't cut the mustard. Just remove the #define and that should take care of all those errors and warnings. You also will have to remove the '+' and '-' signs. Maybe define as "char APlus[2]", etc.

Also "Score * 3 = english_language;" is backwards --- "english_language = Score * 3;"

That should get you started. You have other errors to fix as well.

Way to many warnings/errors with this. Also what is your intent on:

Code:

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while( option > 3 || option < 3 );

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Your options for your switch are for 1,2,3.

Also your function grade_value() is not declaried. Your only function outside of main() is

Code:

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double Grade ( char &Grade )

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Again, your scanf() is expecting a %s, string, yet you are assigning to &Grade which is of type char. This gives only a warning, but is not clean code.

Have you compiled this and have seen these warning and errors yourself?

As already mentiond your #defines are causing most of your troubles, which gives syntax errors with the use of '['.

ive taken you guy's advice thanks alot. and this is an revised version of the program. but i still have errors. can anyone help me with it. i still can't figure out how to solve it. thanks. if possible correct the source code and post it up. thanks alot.

Remove all those defines.

Code:

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//#define char f;

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Local function definitions are illegal (INDENT PROPERLY and you wouldn't have this problem!):

Code:

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void Sem_1 ( void )

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Void is not necessary for inside argument lists in C++ (which is what you're compiling it as):

Code:

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void Sem_1 ()

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Due your indentation problem, the code is all in the wrong places because you missed a }:

Code:

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        do
        {

                printf("enter option here: ");
                scanf("%d",&option);
                switch ( option )
                {
                case 1:

                        system ( "cls" );
                        Sem_1();

                        break;

                case 2:

                        system ( "cls" );
                        Sem_2();

                        break;

                case 3:

                        system ( "cls" );
                        Sem_3();

                        break;
                }
        }
        while( option > 4 || option < 4 );
        return 0;
}

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Missing ;

Code:

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int back_1;

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writing_for_mass_communication: undeclared variable.

Code:

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writing_for_mass_communication = Score * 3;

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Code:

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Score * 3 = computer_studies;

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Perhaps you intended:

Code:

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computer_studies = Score * 3;

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Missing ;

Code:

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printf("press 0 to go back to option menu");

---

Code:

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scanf("%d", &back_1);

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computer_studies: undeclared variable.

Code:

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computer_studies = Score * 3;

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gpa_sem_1: undeclared variable.

Code:

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cgpa_sem_2 = ( ( gpa_sem_1 + gpa_sem_2 ) / 2 );

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Missing ;

Code:

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printf("press 0 to go back to option menu");
scanf("%d", &back_2);

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gpa_sem_1, gpa_sem_2: undeclared variables.

Code:

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cgpa_sem_3 = ( ( gpa_sem_1 + gpa_sem_2 + gpa_sem_3 ) / 3 );

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Missing ;

Code:

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printf("press 0 to go back to option menu")
scanf("%d", &back_3)

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Completely wrong in all sorts of ways and expectations.

Code:

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        if (strcmp( Grade, A+ || a+ == 0 ))
        {
                Score += 4.00;
        }
        else if (strcmp( Grade, A- || a- == 0 ))
        {
                Score += 3.70;
        }
        else if (strcmp( Grade, B+ || b+ == 0 ))
        {
                Score += 3.30;
        }
        else if (strcmp( Grade, B || b == 0 ))
        {
                Score += 3.00;
        }
        else if (strcmp( Grade, B- || b- == 0))
        {
                Score += 2.70;
        }
        else if (strcmp( Grade, C+ || c+ == 0 ))
        {
                Score += 2.30;
        }
        else if (strcmp( Grade, C || c == 0 ))
        {
                Score += 2.00;
        }
        else if (strcmp( Grade, D || d == 0 ))
        {
                Score += 1.00;
        }
        else if (strcmp( Grade, F || f == 0 ))
        {
                Score += 0.00;
        }
        else
        {
                printf( "invalid grade\n" );
                printf( "please enter again: " );
        }

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Score: undeclared variable.

Code:

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Score += 4.00;

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Uninitialized variables public_speaking and writing_for_mass_communication used.

Code:

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gpa_sem_1 = ( ( english_language + public_speaking + principles_of_accounting +
principles_of_economics + general_mathematics_1 + computer_studies ) / 18 );

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You obviously know nothing about C or C++. Go back to school. This isn't a playground.
Make a real effort in making a program and start of small. When you've mastered the basics, come back and we'll help you.

how do i solve the three unresolced external symbols. i know it has got to do i with the function calling. but not sure how to solve it.
any advice on what logic should i use to do error warnings and go back to the previous data entry.
i am feeling the error is from this part but i am not sure what is it trying to point out.

//function prototype
double sem_1 ( void );
double sem_2 ( double );
double sem_3 ( double, double );

thanks for you help.

If you post WHICH symbols are unresolved, then that would help us quite a bit.

--
Mats

Why your c file has cpp extention? cpp is for C++, C-file in general have to have c-extention

C code can be compiled as C++ code, and to be honest, I would recommend it that way.

Quote:

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Originally Posted by Elysia

C code can be compiled as C++ code, and to be honest, I would recommend it that way.

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I wouldn't. If you want to write C++ - do it. If you are using C - use it. Do not mix 2 different languages in one compilation unit

But if i have C code i need to use in C++, would the recommended way be linking the object files to a library and #including their interface? When i inline functions in C header files, either as #define Macros or using the inline directive, then there are issues i should care for? I have not used C++ that much, but am not a total stranger, and i would like to know what is the best way to make both happy.

Quote:

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Originally Posted by Elysia

C code can be compiled as C++ code

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That's not entirely true, this is legal C code, but it won't compile on a C++ compiler for obvious reasons:

Code:

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int class = 0;

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This ofcourse applies to all keywords in C++ that C doesn't have. Also, why would you recommend a C++ compiler for C code?

C++ has a stronger type-checking than C, so that would be one reason to compile code with C++ compiler even tho' the code itself is C.

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Mats