Having a problem using '-'

[DJ007]

Hi im having a problem whem attempting to calculate using negative
with small numbers example==-2 1 + im getting the error message instead of the answer. PLZ HELP!!!

#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <string.h>
#include <math.h>
#include <ctype.h>


#define ERROR5 "Input strings too long. Applies to numbers and operators."
#define ERROR4 "Operation not possible."
#define ERROR3 "Division by zero."
#define ERROR2 "Unknown operation."
#define ERROR1 "Number contains alphabetic characters."
#define MAX 11

void main()
{
    float Divide1,Divide2 = 0.0;
    void function(char,float,float);

    int Num1, x=0;
    int Num2,y;
    char isdigit(char);
    char Str2[MAX];
    char Str1[MAX];
    char Operator;

    do
    {
    printf("\nPlease enter the required calculation\n");
    scanf("%s %s", &Str1, &Str2);

    if (strlen(Str1) > MAX-1)
        printf(ERROR5);
    else if (strlen(Str2) > MAX-1)
        printf(ERROR5);

    Divide1= atof(Str1);
    Divide2= atof(Str2);

    if  ((*Str2) == 'S')
        printf("%f\n",sqrt(Divide1) );
    else if ((*Str2) == 'R')
        printf("=%f\n",1/Divide1 );

    else for (y=0; y<MAX; y++)
    {
        if(isdigit (Str1[y] & Str2[y]))
            x = 6;
        else if (x != 6)
            x = 2;
    }

    if(x == 2)
        printf(ERROR1);
    else if (x == 6)
    {
        scanf(" %s", &Operator);
        Num1= atoi(Str1);
        Num2= atoi(Str2);
        switch(Operator)
        {
            case '+':
                printf("= %d", Num1+Num2);
                break;
            case '-':
                printf("= %d \n", Num1-Num2);
                break;
            case '*':
                printf("=%d ", Num1*Num2);
                break;
            case '/':
                function(*Str2,Divide1,Divide2);
                break;
            default:
                printf(ERROR2);

        }
    }}
while((*Str1) != "EXIT");

getch();
}

void function(char Str2, float Divide1, float Divide2)
{

if(Str2 == '0')
    printf(ERROR3);
else
   printf("=%f",Divide1/Divide2);

}

[cpjust]

What line is giving you the error and what is the error message?

[Elysia]

And while we're waiting, take a look at this.
http://cpwiki.sf.net/void_main

[rits]

Hi,

I am new to c programming. While looking at ur code I came across a strange thing.

The line


void function(char,float,float);

in main is a function prototype. My question is can function prototype delclare inside a function or it should be outside of all the functions????

[BEN10]

yes the function can be declared inside main.any function can be declared inside main but should be called after the declaration.

[Adak]

I work it like this - if the function is only called by one other function, then I put it's prototype in that calling function.

If the function is going to be called by more than one other function, then I put it before main(), making it known to all the functions in the program.

I'm not as consistent about this as I'd prefer, but that's the plan.

[rits]

BEN10 and ADAK thanks for ur reply.....

[Elysia]

I always put them at top (or in a header). Easier to find, easier to locate, easier to change.
And you don't have to move them in case you change your mind.
We should also mention that this is a very poor way of making a prototype since it lacks the name of the parameters it accepts. It's pretty much impossible to figure out what it accepts by looking at the prototype because of that.

[rits]

Yes Elysia, I agree with you

[DJ007]

Ive fixed that problem but now I have another little problem when i input the first equation using +,-,*,/ the answer is correct but when input of the second equation using Squareroot or Reciprocal it seems to be waiting for the Operator. it shouldnt happen if the second string is R or S??
If using Reciprocal or Squareroot in the first equation it works fine until i use +.-,*,/ then the following Reciprocal,Squareroot doesnt work

HELP!!