I need help.

[Shooby]

I am currently writing a program in C for a currnecy converter.
I have hit a wall right at the start:


float ster;
float char;
ster=0;
eur=0;
ster=eur*0.7:

printf("Enter amount in Euro\n");
scanf("%f", &eur);

printf("The equivalent in Sterling is %f", &ster);


This much doesn't work!
The equivalent just prints off as 0.0000
Hmm?

[JKForCForums]

You have intialized eur=0;
do initialize
float eur=0.0;

[Nyda]

C is not a logical language. First you need to have your input, then you can do some calculations with it and only when that is done, you can output it.

also

 printf("The equivalent in Sterling is %f", &ster);

should probably be

 printf("The equivalent in Sterling is %f", ster);

Since you're new, welcome, and please use code tags.

[Shooby]

Ah yes. Thanks.
Another quick question, is it possible to nest switches or will they overlap and cause all sorts of infinite loops etc.?

[Nyda]

is it possible to nest switches or will they overlap and cause all sorts of infinite loops etc.?

Like how? I don't see how the compiler could confuse a switch statement if you use { }. You should better stay away from nested if/else clauses without { } though, if that's what you're referring to.

[Shooby]

This seems to interfere with itself, maybe I have made an obvious mistake:

#include <stdio.h>

main()
{
char ch;
int num;
float eur=0.0;
float ster=0.0;




printf("Choose a country for currency conversion\n");
printf ("A.Britain\nB.Denmark\nC.Japan\nD.USA\nE.Exit\n"); 
scanf("%c", &ch);
switch (ch)   
{
	case 'a' :
 		printf("Do you wish to convert:\n");
 		printf("1.From Euro to Sterling\n2.From Sterling to Euro\n");
 		scanf("%d", &num);
      switch (num)
      {
      	case '1' :
         	printf("Enter amount in Euro\n");
  				scanf("%f", &eur);
  				ster=eur*0.70;
  				printf("The equivalent in Sterling is %4.2f", ster);
            break;
         case '2'  :
			   printf("Enter amount in Sterling\n");
            break;
         default :
         	printf("invalid entry");
      }

   case 'b' :
   	printf("YO");
      break;

   default :
   	printf("invalid entry");

[Nyda]

No, that's an issue with your scanf usage. It's one of those functions that give normal people a headache. You could read a string instead of a single character. Like...

char num[2];
...
scanf("%2s", num);
switch (*num)
    {
...

Same for num. Or read integer - probably the better solution unless you really need 'a', 'b', 'c'...

[Shooby]

I don't really understand what you just told me.

[Shooby]

Right, I have gotten this far, but it doesn't seem to work:

#include <stdio.h>

main()
{
char ch;
char ch1;
float eur=0.0;
float ster=0.0;




printf("Choose a country for currency conversion\n");
printf ("A.Britain\nB.Denmark\nC.Japan\nD.USA\nE.Exit\n");  scanf("%c", &ch);
switch (ch)
{
	case 'a' :
   case 'A' :
 		printf("Do you wish to convert:\n");
 		printf("1.From Euro to Sterling\n2.From Sterling to Euro\n");
 		scanf("%c", &ch1);
      if (ch1='1')
      {
      	printf("Enter amount in Euro\n");
       	scanf("%f", &eur);
       	ster=eur*0.70;
       	printf("The equivalent in Sterling is %4.2f", ster);
      }
      if (ch1='2')
      {
       	printf("Enter amount in Sterling\n");
      }
      else
      {
      	printf("invalid entry");
      }

   case 'b' :
   case 'B' :
   	printf("continue program...");
      break;

   default :
   	printf("invalid entry");
}
}

Any ideas?

[DavT]

One quick fix to solve your 'interfering' issue is that you have missed the 'break' at the end of case 'A'. You also should really break after the default case - more of a style thing really.

Once you have that fixed you should be able to reinstate the switch for ch1 - which is more stylish than the if ... else if ... else structure that you (should) have at the moment.

[Shooby]

Thanks very much.
How would I go about looping back to the original menu after each conversion? Do I use the do-while statement?

[DavT]

Yes.

[Shooby]

I put the break in on case 'A' but now the program freezes immediatley after case A is entered.

[DavT]

Could you post your code? Otherwise we'll just be guessing. An datking a stab in the dark, you did put the break in the line directly above "case'b'" didn't you?

[Shooby]

This is it, but putting the break above case 'b' doesn't work either.

#include <stdio.h>

main()
{
char ch;
char ch1;
float eur=0.0;
float ster=0.0;




printf("Choose a country for currency conversion\n");
printf ("A.Britain\nB.Denmark\nC.Japan\nD.USA\nE.Exit\n");  
scanf("%c", &ch);
switch (ch)
{
	case 'a' :
   case 'A' :
 		printf("Do you wish to convert:\n");
 		printf("1.From Euro to Sterling\n2.From Sterling to Euro\n");
 		scanf("%c", &ch1);
      break;

      switch (ch1)
      {
      	case '1' :
      		printf("Enter amount in Euro\n");
       		scanf("%f", &eur);
       		ster=eur*0.70;
       		printf("The equivalent in Sterling is %4.2f", ster);
         	break;

         case '2' :
       		printf("Enter amount in Sterling\n");
            scanf("%f", &ster);
            eur=ster*1.42;
            printf("The equivalent in Euro is %4.2f", eur);
         	break;

         default:
      		printf("invalid entry");
         	break;
      }


   case 'b' :
   case 'B' :
   	printf("...");
      break;

   default :
   	printf("invalid entry");
}
}