# Thread: How to check for minus??

1. ## How to check for minus??

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

#define MAX 11

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

int Num1;
int Num2,y,n=0,k=0,kl,x;
char isdigit(char);
char Str2[MAX];
char Str1[MAX];
char Operator[1],v;
//do-while loop until Exit is Typed
do
{
//Get first string
scanf("%s", Str1);
//Exit program if 'Exit' typed
if (strcmp(Str1,"Exit") == 0)
break;
//Get second string
scanf("%s", Str2);
if (strcmp(Str2,"Exit") == 0)
break;
// if numbers entered are above MAX display error
if (strlen(Str1) > MAX -1)
printf("ERROR5");

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

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

//Calculate Squareroot if string2 is an 'S'
if  ((*Str2) == 'S')
printf("=%f\n",sqrt(Divide1) );
//Calculate Reciprocal if string2 is an 'R'
else if ((*Str2) == 'R')
printf("=%f\n",1/Divide1 );

// Check if strings are alphabetacal
if ((*Str2 != 'S') & (*Str2 != 'R'))
{
y = strlen(Str1);
for(x = 0; x < y; x++)
{
if( !isdigit(Str1[x]) )
{
k=1;
}
}
y = strlen(Str2);
for(x = 0; x < y; x++)
{
if( !isdigit(Str1[x]) )
{
k=1;
}
}
if (k == 1)
{
printf("ERROR1");
}
else
{

scanf(" %s", &Operator);
if (strlen(Operator) > 1)
{
n = 2;
}
if (n != 2)
{
v=Operator[0];
Num1= atoi(Str1);
Num2= atoi(Str2);
//Switch statement to calculate Addition,Subtraction,Multiplication and Division
switch(v)
{
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");

}}
if (n == 2)
{
printf("ERROR2");
}
}
}
n = 0;
k = 0;
fflush(stdin);

}
while(strcmp(Str1, "Exit") != 0);
getch();
}

//function to display error if divide by '0' else division performed
void function(char Str2, float Divide1, float Divide2)
{
if(Str2 == '0')
printf("ERROR3");
else
printf("=%f",Divide1/Divide2);

}```

2. Well uh, maybe like this, which is already in your code
Code:
`case '-':`
Don't you go and just dump a whole lot of code on us, give almost zero exlpanation of what you're wanting to do and expect any kind of helpful response!

How To Ask Questions The Smart Way

3. > void main()
> fflush(stdin);
Read the FAQ, both of these are wrong.