Member Avatar for devel2000

when I run my program in GCC ,there are some problem apperes to me ,,I need help to make it run !!Plz

#include<stdio.h>

#include<stdlib.h>
#include<string.h>
#include<math.h>


   // Declare a few variables 

char InputString[32], type;
int NumValue, sum=0, Length, result;

int main()    //main function
{
printf("Type in a number:");
if(!gets(InputString))         
printf("You did not enter any value:\n");
Length = strlen(InputString); 

if( (result = testnumber())==0 )
{
printf("That is an invalid number!");  // prints That is an invalid number!
exit(0);
}

Asktbase();  //call function Asktbase
//        printf("value of type= %c" , type );

if( (type=='f') &&  (InputString[0]==48))
{
binary_decimal() ; 
exit(0);
}    
    
if(type=='f')
{
printf("Is this number decimal (d) or binary (b)?");
scanf("%c",&type);
if(type=='d') decimal_binary(); 
if(type=='b') binary_decimal(); 
}
else 
{
if( (result = testnumber())==0)
{
printf("That is an invalid number!");
}

Length = strlen(InputString);  //strlen: Find length of string
IsDecimal();

if(type=='d')
{
              if(atoi(InputString)<=255 ) decimal_binary();   //atoi: Convert ASCII string to integer
              else
              {
              printf("That is an invalid number!");
              exit(0);
              }
}
else binary_decimal();
}
}

binary_decimal()   //function to convert binary to decimal number
{
int i, p, a;
for(i=1; i<=Length; i++)
{
if(InputString[Length-i]==49) NumValue=1;
else  NumValue=0; 
                 if(NumValue==1)
                 { 
                 p=i-1;
                 a=pow(2,p);
                 sum=sum+a;
                 }
				 }
printf("Converting binary to decimal. Answer is: %d \n", sum);  // print number binary to decimal
}

decimal_binary()  //function to convert decimal to binary number
{
int dec,i=1,rem,res=0;
dec = atoi(InputString);  // //atoi: Convert ASCII string to integer
   while(dec>0)
    {
	rem=dec%2;
	dec=dec/2;
	res=res+(i * rem);
	i=i*10;
   }
printf("Converting decimal to binary. Answer is: %8.8d",res);    //print number decimal to binary
 }

int testnumber()
{
int i ;      
for(i = 1 ; i <= Length ; i++)
{
if(isdigit(InputString[Length-i]))    //isdigit - test for a decimal digit
return 1 ;    
else return 0 ;                      
}
}

IsDecimal()
{
int i;
for(i = 1 ; i <= Length ; i++)
{

	//ASCII code 50 is equal to Two,51 equal to three, 52 equal to four, 53 equal to five, 54 equal to six, 55 equal to seven, 56 equal to eight, 57 equal to nine

if( ( InputString[Length-i] ==50) ||  ( InputString[Length-i] ==51)||( InputString[Length-i] ==52)||( InputString[Length-i] ==53)
||( InputString[Length-i] ==54)||( InputString[Length-i] ==55)||( InputString[Length-i] ==56)||( InputString[Length-i] ==57))  
type = 'd' ; 
}    
if((InputString[0] ==48) && (type = 'd'))
{
 printf("That is an invalid number!");
 exit(0);
}
}


testbase()
{
int i;
for(i = 1 ; i <= Length ; i++)
{
if( ( InputString[Length-i] !=49) ||  (InputString[Length-i]!=48))  
type = 'd' ; 
}    
}


Asktbase()
{
int i;
for(i = 1 ; i <= Length ; i++)
{
if(   ( InputString[Length-i] ==49) ||  (InputString[Length-i] ==48)   )     //ASCII code 48 is equal to zero and 49 equal to 1
{
    
type='f' ; 
}
else 
{
type='a' ;
Length = i - 1 ;
}
}    
}

-------------
my error
assign1.c: In function `int main()':
assign1.c:19: error: `testnumber' was not declared in this scope
assign1.c:25: error: `Asktbase' was not declared in this scope
assign1.c:30: error: `binary_decimal' was not declared in this scope
assign1.c:38: error: `decimal_binary' was not declared in this scope
assign1.c:39: error: `binary_decimal' was not declared in this scope
assign1.c:43: error: `testnumber' was not declared in this scope
assign1.c:49: error: `IsDecimal' was not declared in this scope
assign1.c:53: error: `decimal_binary' was not declared in this scope
assign1.c:60: error: `binary_decimal' was not declared in this scope
assign1.c: At global scope:
assign1.c:65: error: ISO C++ forbids declaration of `binary_decimal' with no type
assign1.c: In function `int binary_decimal()':
assign1.c:74: warning: converting to `int' from `double'
assign1.c: At global scope:
assign1.c:82: error: ISO C++ forbids declaration of `decimal_binary' with no type
assign1.c: In function `int testnumber()':
assign1.c:100: error: `isdigit' was not declared in this scope
assign1.c: At global scope:
assign1.c:107: error: ISO C++ forbids declaration of `IsDecimal' with no type
assign1.c:127: error: ISO C++ forbids declaration of `testbase' with no type
assign1.c:138: error: ISO C++ forbids declaration of `Asktbase' with no type
>Exit code: 1

Edited by Nick Evan because: Added CODE-tags
  • 3 Contributors
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  • 1 Day Discussion Span
  • Latest Post Latest Post by sree_ec

Dani AI

Generated

Brief, focused diagnosis for the errors shown in 's messages and concrete fixes that complement and 's suggestions.

The compiler output points to a few consistent problems: (1) functions are used before being declared — add prototypes above main or move full definitions below main; (2) several functions lack an explicit return type (K&R style) — C++ (and modern C) require int/void return types; (3) isdigit is undeclared — #include <ctype.h> (or <cctype> + std::isdigit for C++) is missing and calls should use isdigit((unsigned char)ch); (4) logical/assignment bugs (single = used where == was intended, and || used where && should be) will make checks always succeed or fail; (5) gets() is unsafe and removed — use fgets() and strip the newline; (6) the command line shows g++ compiling a .c file: either compile with gcc for C or adapt the code for C++ (headers and std:: names); (7) pow() returns double so the warning is expected — prefer integer bit operations for binary math.

Minimal helpful snippets (add these before main):

/* add this header */
#include <ctype.h>

/* add prototypes so the compiler knows the functions before use */
int testnumber(void);
void Asktbase(void);
void binary_decimal(void);
void decimal_binary(void);
int IsDecimal(void);
void testbase(void);

Concrete logic tips (no duplication of the posted body): test-number routines must scan the whole string and only return "valid" after all characters are checked (avoid returning from the loop on the first character). Replace assignments inside if conditions (type = 'd') with comparisons (type == 'd'). For binary-vs-decimal checks, test "neither '0' nor '1'" with &&, not ||. Replace gets() with fgets() and trim the trailing newline. Compile with warnings enabled to catch the root cause early:

gcc -Wall -Wextra -std=c99 me.c -o me.exe

As and noted, posting the exact current source inside the forum code tags (so line numbers match) will make any remaining errors straightforward to pinpoint.

Recommended Answers

All 8 Replies

Member Avatar for N1GHTS

I haven't reviewed the whole code, especially since its got no indentation and its not in code tags, but the first error is happening because you have your testnumber() function defined AFTER you first used it. The compiler doesn't know what testnumber() is unless you at least declare it before the first use. It can be defined later on in the code but it must first be declared by writing "int testnumber();" at the top of your C code, or at least move your main() function at the bottom of the page.

My main advice is to learn how to effectively use headers. A well written C program has every C code complimented with a header with all the declarations inside of it which you #include from your C file.

Member Avatar for devel2000

your advice was great ,,, thanks it's been reduce the mistakes to few ,, that what left to me

>"C:\Program Files\gcc\bin/g++" -Os -mconsole -g me.c -o me.exe
me.c:11: error: expected initializer before ')' token
me.c:68: error: ISO C++ forbids declaration of `binary_decimal' with no type
me.c: In function `int binary_decimal()':
me.c:77: warning: converting to `int' from `double'
me.c: At global scope:
me.c:85: error: ISO C++ forbids declaration of `decimal_binary' with no type
me.c: In function `int testnumber()':
me.c:103: error: `isdigit' was not declared in this scope
me.c: At global scope:
me.c:110: error: ISO C++ forbids declaration of `IsDecimal' with no type
me.c:130: error: ISO C++ forbids declaration of `testbase' with no type
>Exit code: 1

Member Avatar for N1GHTS

Since you changed you code to fix that one bug, now your errors are inconsistent with your original code.

You need to use code tags when you copy your code in here, its very important.

Member Avatar for devel2000

what do you need by code tags?
anyway thanks for your helping
that what left with me ,, do you have hint how to do them

>"C:\Program Files\gcc\bin/g++" -Os -mconsole -g me.c -o me.exe
me.c:11: error: expected initializer before ')' token
me.c: In function `int binary_decimal()':
me.c:78: warning: converting to `int' from `double'
me.c: In function `int testnumber()':
me.c:104: error: `isdigit' was not declared in this scope
>Exit code: 1

Member Avatar for N1GHTS

On the message box you are typing inside of, there is an icon that saids in big letters Code. You need to use that to put your NEW code inside of. You keep showing errors for code we have not seen yet. Your old code is incompatible with your new errors.

Edited by Reverend Jim because: Fixed formatting
Member Avatar for devel2000 
>"C:\Program Files\gcc\bin/g++"  -Os -mconsole -g me.c -o me.exe
me.c:11: error: expected initializer before ')' token
me.c: In function `int binary_decimal()':
me.c:78: warning: converting to `int' from `double'
me.c: In function `int testnumber()':
me.c:104: error: `isdigit' was not declared in this scope
>Exit code: 1
Member Avatar for N1GHTS

... :|

Well, at least you got the (code) part right...

Hmmm...

How do I explain that the error you keep showing us is for code no one in this entire world can actually see but yourself.

How do I explain that the line numbers in the error messages do not apply to obsolete code?

But more importantly, How do I explain that what I need in the code-tags is not the error, but the CODE ITSELF!

Perhaps its impossible to ever know for sure. A great paradox I suppose.

s23.jpg 16.23 KB
Edited by mike_2000_17 because: Fixed formatting
commented: ;) +1
Member Avatar for sree_ec 
>"C:\Program Files\gcc\bin/g++"  -Os -mconsole -g me.c -o me.exe
me.c:11: error: expected initializer before ')' token
me.c: In function `int binary_decimal()':
me.c:78: warning: converting to `int' from `double'
me.c: In function `int testnumber()':
me.c:104: error: `isdigit' was not declared in this scope
>Exit code: 1

Just Post your code also inside the code tags.
To help with your issue, members here needs to see the code also.
They cannot guess the code from your errors.

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