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starting a calculator program in C

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Join Date: Jan 2007

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cusado

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starting a calculator program in C

Feb 2nd, 2007

im writing a calculator program in c and having some trouble..
basically it needs to have + - / * ^ functions as well as an integer only mode

the code so far

 Help with Code Tags 
 c Syntax (Toggle Plain Text) 
 
#include <stdio.h>
#include <ctype.h>
#include <math.h>
 
 
 
int main(int argc, char *argv[]) {
    float acc, num;
    char op;
 
 
float do0p(char op, float num1, float num2) {
    select (op) {
        case + : return num1 + num2;
            break;
        case - : return num1 - num2;
            break;
        case * : return num1 * num2;
            break;
        case / : return num1 / num2;
            break;    
        case ^ : return pow(num1,num2);
            break;
        default: return num1;
    }
}
 
 
 
    printf("Welcome to calculator!\n");
    while(1) {
        scanf("%f", acc);
        while(1) {
            do op = getchar(); while(isspace(op));
            if(op == 'q') return 0;
            else if(op == 'c') break;
        scanf("%f", num);
            acc = do0p(op, acc, num);
            printf("%d", acc);
        }
    }
 
 
 
 
 
 
    return 0;
 
 
 
 
}
 
#include <stdio.h>
#include <ctype.h>
#include <math.h>



int main(int argc, char *argv[]) {
    float acc, num;
    char op;


float do0p(char op, float num1, float num2) {
    select (op) {
        case + : return num1 + num2;
            break;
        case - : return num1 - num2;
            break;
        case * : return num1 * num2;
            break;
        case / : return num1 / num2;
            break;    
        case ^ : return pow(num1,num2);
            break;
        default: return num1;
    }
}



    printf("Welcome to calculator!\n");
    while(1) {
        scanf("%f", acc);
        while(1) {
            do op = getchar(); while(isspace(op));
            if(op == 'q') return 0;
            else if(op == 'c') break;
        scanf("%f", num);
            acc = do0p(op, acc, num);
            printf("%d", acc);
        }
    }






    return 0;




}

for somereason the program isnt working and i still am not sure how to add an integer only mode
any help would be nice

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Join Date: Oct 2006

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niek_e

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Re: starting a calculator program in C

Feb 2nd, 2007

There are some things wrong with you program:

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float do0p(char op, float num1, float num2) {

This function is made inside of main() which is impossible.

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select (op) {

I think you mean switch() ?

•

case +

I think you mean '+' instead of +
Same thing with the other chars.

you really should use code-indention, this is very hard to read.

regards Niek

Last edited by niek_e; Feb 2nd, 2007 at 6:59 am.

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cusado

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Re: starting a calculator program in C

Feb 2nd, 2007

hm i changed the code and it complies now, but when i try to inter a number, an error appears

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Colin Mac

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Posting Whiz

Re: starting a calculator program in C

Feb 2nd, 2007

scanf() needs an ampersand before the variable name when inputting numbers.

scanf("%f", &num);

Last edited by Colin Mac; Feb 2nd, 2007 at 10:17 am.

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WaltP

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Re: starting a calculator program in C

Feb 2nd, 2007

•

Originally Posted by cusado

hm i changed the code and it complies now, but when i try to inter a number, an error appears

You must give us details. "An error" can be any of 300+ things.

Explain fully
1) what is wrong
2) where the problem is
3) what it should do instead
4) cut and paste errors (don't paraphrase them)

That way our psychic powers don't have to be used.

The 3 Laws of the Procrastination Society:
1) Never do today that which can be put off until tomorrow
2) Tomorrow never comes

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Join Date: Jan 2007

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cusado

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Re: starting a calculator program in C

Feb 2nd, 2007

Well the updated code is now

 Help with Code Tags 
 c Syntax (Toggle Plain Text) 
#include <stdio.h>
#include <ctype.h>
#include <math.h>
 
float do0p(char op, float acc, float num) {
    switch (op) {
        case '+' : return acc + num;
            break;
        case '-' : return acc - num;
            break;
        case '*' : return acc * num;
            break;
        case '/' : return acc / num;
            break;    
        case '^' : return pow(acc,num);
            break;
        default: return acc;
    }
}
 
 
int main(int argc, char *argv[]) {
    float acc, num;
    char op;
 
    printf("Welcome to calculator!\n");
    while(1) {
        printf("enter first number\n");
        scanf("%f", &acc);
            while(1) {
                do op = getchar(); while(isspace(op));
                if(op == 'q') return 0;
                else if(op == 'c') break;
                printf("enter second number\n");
                scanf("%f", &num);
            acc = do0p(op, acc, num);
            printf("%d", &acc);
        }
    }
 
 
 
 
 
 
    return 0;
 
 
 
 
}
#include <stdio.h>
#include <ctype.h>
#include <math.h>

float do0p(char op, float acc, float num) {
    switch (op) {
        case '+' : return acc + num;
            break;
        case '-' : return acc - num;
            break;
        case '*' : return acc * num;
            break;
        case '/' : return acc / num;
            break;    
        case '^' : return pow(acc,num);
            break;
        default: return acc;
    }
}


int main(int argc, char *argv[]) {
    float acc, num;
    char op;

    printf("Welcome to calculator!\n");
    while(1) {
        printf("enter first number\n");
        scanf("%f", &acc);
            while(1) {
                do op = getchar(); while(isspace(op));
                if(op == 'q') return 0;
                else if(op == 'c') break;
                printf("enter second number\n");
                scanf("%f", &num);
            acc = do0p(op, acc, num);
            printf("%d", &acc);
        }
    }






    return 0;




}

i type in 4
+
5
and it returns 1245060
is there something wrong with the case portion?

Last edited by cusado; Feb 2nd, 2007 at 3:14 pm.

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cusado

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Re: starting a calculator program in C

Feb 2nd, 2007

also, in pellesC i keep getting a POLINK: fatal error: Access is denied.
message, but if i put the same code in Dev-C++ it doesnt show up(im programming Dev-C++ in C as well)

Last edited by cusado; Feb 2nd, 2007 at 5:11 pm.

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Join Date: Dec 2006

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Ravalon

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Re: starting a calculator program in C

Feb 2nd, 2007

•

Originally Posted by cusado

is there something wrong with the case portion?

Nope, the problem is with how you print the result.

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
printf("%d", &acc);
printf("%d", &acc);

&acc means the address of acc, and %d expects an int. If you change %d to %f and &acc to acc, things begin to work.

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
printf( "%f", acc );
printf( "%f", acc );

The rules for using scanf() and printf() are frustratingly different, especially when you know everything is right but still keep getting 0 instead of a number you expect.

•

Originally Posted by cusado

also, in pellesC i keep getting a POLINK: fatal error: Access is denied.
message, but if i put the same code in Dev-C++ it doesnt show up(im programming Dev-C++ in C as well)

Is this the first program you've tried to build in Pelles C? It could be a corrupt installation.

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