Basic Sum Calculator

This is a discussion on Basic Sum Calculator within the C Programming forums, part of the General Programming Boards category; Hey everybody, I started programming C today, and here I am posting my first doubt: Code: #include <stdio.h> #include <conio.h> ...

  1. #1
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    Thumbs down Basic Sum Calculator

    Hey everybody, I started programming C today, and here I am posting my first doubt:

    Code:
    #include <stdio.h>
    #include <conio.h>
    
    int main(void)
    {   
        int  num1;
        int   num2;
        int  sum;
        
        printf("Enter your first number: ");
        
        scanf("%d", &num1);
        
        printf("Enter your second number: ");
        
        scanf("%d", &num2);
        
        sum = num1+num2;
        
        printf("The sum is %d", sum);
        
        
        getch();
    }
    This works fine as a sum calculator, but only with INT values (I'm a programmer for a long time, but I started C today, used to program Java and Python, so I know quite a lot).

    Whenever I try to use FLOAT values, it goes crazy, try it on your computer please.



    Thanks in advance,

    ScoutDavid

  2. #2
    Registered User Char*Pntr's Avatar
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    Just declare your variables as floats, example float sum.

    here's a link that I still use:

    C variable types and declarations - Wikipedia, the free encyclopedia

  3. #3
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    Code:
    #include <stdio.h>
    #include <conio.h>
    
    int main(void)
    {   
        float  num1;
        float   num2;
        float  sum;
        
        printf("Enter your first number: ");
        
        scanf("%d", &num1);
        
        printf("Enter your second number: ");
        
        scanf("%d", &num2);
        
        sum = num1+num2;
        
        printf("The sum is %d", sum);
        
        
        getch();
    }
    Thanks for the link very useful, but I followed your tip and still crazy, it says the result is 0 even before I type the second number...

  4. #4
    ... kermit's Avatar
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    You need to use %f in scanf if you are trying to get a floating point number. Same goes for printf. %d is to get an int (scanf), or print an int (printf).
    Last edited by kermit; 09-25-2010 at 12:57 PM.

  5. #5
    Registered User Char*Pntr's Avatar
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    Quote Originally Posted by ScoutDavid View Post
    Code:
    #include <stdio.h>
    #include <conio.h>
    
    int main(void)
    {   
        float  num1;
        float   num2;
        float  sum;
        
        printf("Enter your first number: ");
        
        scanf("%d", &num1);
        
        printf("Enter your second number: ");
        
        scanf("%d", &num2);
        
        sum = num1+num2;
        
        printf("The sum is %d", sum);
        
        
        getch();
    }
    Thanks for the link very useful, but I followed your tip and still crazy, it says the result is 0 even before I type the second number...
    I did NOT want to make all your corrections, otherwise you wont learn. You
    also have to change the scanf() format. You still have it scanning for type int,
    instead of type float.

    This question is answered on the FAQ here, shall I search for it, or do you want
    to give it a try?

    Edit:

    Nevermind, you were spoon fed the answer.
    Last edited by Char*Pntr; 09-25-2010 at 01:07 PM.

  6. #6
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    Code:
    #include <stdio.h>
    
    int main(void)
    {
        float  num1;
        float  num2;
        float  sum;
    
        printf("Enter your first number: ");
    
        scanf("%f", &num1);
    
        printf("Enter your second number: ");
    
        scanf("%f", &num2);
    
        sum = num1+num2;
    
        printf("The sum is %f", sum);
    
    
        getch();
    }
    This might help. U need to change the input and output to float variables also.

  7. #7
    Registered User Char*Pntr's Avatar
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    How Do I? check out this FAQ:

    Cprogramming.com FAQ

  8. #8
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    I've gotten there:

    "You need to use %f in scanf if you are trying to get a floating point number."

    Thank you very much!

  9. #9
    Registered User Char*Pntr's Avatar
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    Quote Originally Posted by ScoutDavid View Post
    I've gotten there:

    "You need to use %f in scanf if you are trying to get a floating point number."

    Thank you very much!
    And while you're in the FAQ, check out the rest of it! There's a lot of answers
    there, so many, you'll learn the answers before you get a question.

    (The How Do I.....)

  10. #10
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    #include <stdio.h>
    #include <conio.h>

    int main(void)
    {
    float num1;
    float num2;
    float sum;

    printf("Enter your first number: ");

    scanf("%f", &num1);

    printf("Enter your second number: ");

    scanf("%f", &num2);

    sum = num1+num2;

    printf("The sum is %f", sum);


    getch();
    }

    3.4 + 52 = 55.400002?!!

    What the heck?

  11. #11
    Registered User Char*Pntr's Avatar
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    Quote Originally Posted by ScoutDavid View Post

    What the heck?

    Hmmm... maybe I should have directed you to this link first:

    How To Ask Questions The Smart Way

  12. #12
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    A float is only accurate to a few decimal places, but you can use:
    Code:
    printf("The sum is %.2f", sum);
    to force it to show to 2 decimal places.

  13. #13
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    Quote Originally Posted by Jamdog View Post
    A float is only accurate to a few decimal places, but you can use:
    Code:
    printf("The sum is %.2f", sum);
    to force it to show to 2 decimal places.

    Thank you very much!

  14. #14
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    Welcome to the forum, David!

    Now repeat after me:

    "On my honor, I will do my best to do my duty, and always post my code with code tags around it."

    The forum will make your code miserable to study, if you don't use code tags (highlight your code and click on the # icon in the advanced editing window of the forum).

    With apologies to Baden-Powell.

  15. #15
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    "On my honor, I will do my best to do my duty, and always post my code with code tags around it."


    I did it actually, not hightlight but code it

    I'm in a Python Forum as well and am a long time programmer, I guess i know the rules :lol:

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