I need help.

This is a discussion on I need help. within the C Programming forums, part of the General Programming Boards category; I am currently writing a program in C for a currnecy converter. I have hit a wall right at the ...

  1. #1
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    I need help.

    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?

  2. #2
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    Initialization problem

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

  3. #3
    not-a-geek
    Join Date
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    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

    Code:
     printf("The equivalent in Sterling is %f", &ster);
    should probably be

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

    Since you're new, welcome, and please use code tags.
    main() { int O[!0<<~-!0]; (!0<<!0)[O]+= ~0 +~(!0|!0<<!0); printf("a function calling "); }

  4. #4
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    Ah yes. Thanks.
    Another quick question, is it possible to nest switches or will they overlap and cause all sorts of infinite loops etc.?

  5. #5
    not-a-geek
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    Quote Originally Posted by Shooby
    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.
    main() { int O[!0<<~-!0]; (!0<<!0)[O]+= ~0 +~(!0|!0<<!0); printf("a function calling "); }

  6. #6
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    This seems to interfere with itself, maybe I have made an obvious mistake:

    Code:
    #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");

  7. #7
    not-a-geek
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    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...

    Code:
    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'...
    main() { int O[!0<<~-!0]; (!0<<!0)[O]+= ~0 +~(!0|!0<<!0); printf("a function calling "); }

  8. #8
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    I don't really understand what you just told me.

  9. #9
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    Right, I have gotten this far, but it doesn't seem to work:

    Code:
    #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?

  10. #10
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    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.
    DavT
    -----------------------------------------------

  11. #11
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    Thanks very much.
    How would I go about looping back to the original menu after each conversion? Do I use the do-while statement?

  12. #12
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    Yes.
    DavT
    -----------------------------------------------

  13. #13
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    I put the break in on case 'A' but now the program freezes immediatley after case A is entered.

  14. #14
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    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?
    DavT
    -----------------------------------------------

  15. #15
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    This is it, but putting the break above case 'b' doesn't work either.


    Code:
    #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");
    }
    }

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