handling 2D array..

i got an array
char f[3][20];

so when i am doing

Code:

---

fputs(f[equal],common);

---

why i am getting
error C2107: illegal index, indirection not allowed
my code is:

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define false 0
#define true 1

char* equal(char*f1,char*f2,char*f3);
  int smallest(char*f1,char*f2,char*f3);
int main()
{

        FILE *file[3];
        FILE *common;
       
        char f[3][20];
       
        int small;
    char* equall;       
        file[1]=fopen("c:\\1.txt","r");
        file[2]=fopen("c:\\2.txt","r");
        file[3]=fopen("c:\\3.txt","r");
        common=fopen("c:\\common.txt","w");
        fscanf(file[1],"%9s",f[1]);
        fscanf(file[2],"%9s",f[2]);
        fscanf(file[3],"%9s",f[3]);
        while(fgetc(file[1])!=NULL||fgetc(file[2])!=NULL||fgetc(file[3])!=NULL)
        {
            small=smallest(f[1],f[2],f[3]);
            equall=equal(f[1],f[2],f[3]);
               
                fputs(f[equal],common);
                fputc('\n',common);
                fscanf(file[small],"%20s",f[small]);
        }

        fclose(file[1]);
        fclose(file[2]);
        fclose(file[3]);
        return 0;
}

int smallest(char*f[1],char*f[2],char*f[3])
{
    int i=1;
        char* pLowest = f[1];
    if(strcmp(pLowest, f[2]) > 0)
                i=2;
      pLowest = f[2];
      if(strcmp(pLowest, f3) > 0)
      pLowest = f[3];
          i=3;
      return i;
}

  int equal(char*f1,char*f2,char*f3)
  {
         
    if(strcmp(f1,f3)==0)
        {
      return  1;
        }
    if(strcmp(f2,f3)==0)
        {
      return  2;
        }
          return NULL;
  }

---

I think you meant equall, not equal.

i get a whole lot more of errors and warning...you better check them too.

Code:

---


[c_d@localhost C scratchpad]$ gcc temp.c
temp.c: In function ‘main’:
temp.c:26: warning: comparison between pointer and integer
temp.c:26: warning: comparison between pointer and integer
temp.c:26: warning: comparison between pointer and integer
temp.c:31: error: array subscript is not an integer
temp.c: At top level:
temp.c:42: error: redefinition of parameter ‘f’
temp.c:42: error: previous definition of ‘f’ was here
temp.c:42: error: redefinition of parameter ‘f’
temp.c:42: error: previous definition of ‘f’ was here
temp.c:42: error: conflicting types for ‘smallest’
temp.c:8: error: previous declaration of ‘smallest’ was here
temp.c: In function ‘smallest’:
temp.c:49: error: ‘f3’ undeclared (first use in this function)
temp.c:49: error: (Each undeclared identifier is reported only once
temp.c:49: error: for each function it appears in.)
temp.c: At top level:
temp.c:55: error: conflicting types for ‘equal’
temp.c:7: error: previous declaration of ‘equal’ was here
temp.c: In function ‘equal’:
temp.c:66: warning: return makes integer from pointer without a cast
[c_d@localhost C scratchpad]$

---

isnt equal a function? if you want it to be the index then

it should be

f[equal(parameters)] and since equal() returns int it wouldnt be any problems

ok i solved this error but still i have this 2d array problem
c(42) : error C2086: 'char **f' : redefinition

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define false 0
#define true 1

char* equal(char*f1,char*f2,char*f3);
  int smallest(char*f1,char*f2,char*f3);
int main()
{

        FILE *file[3];
        FILE *common;
       
        char f[3][20];
       
        int small;
    int equall;       
        file[1]=fopen("c:\\1.txt","r");
        file[2]=fopen("c:\\2.txt","r");
        file[3]=fopen("c:\\3.txt","r");
        common=fopen("c:\\common.txt","w");
        fscanf(file[1],"%9s",f[1]);
        fscanf(file[2],"%9s",f[2]);
        fscanf(file[3],"%9s",f[3]);
        while(fgetc(file[1])!=NULL||fgetc(file[2])!=NULL||fgetc(file[3])!=NULL)
        {
            small=smallest(f[1],f[2],f[3]);
            equall=equal(f[1],f[2],f[3]);
               
                fputs(f[equall],common);
                fputc('\n',common);
                fscanf(file[small],"%20s",f[small]);
        }

        fclose(file[1]);
        fclose(file[2]);
        fclose(file[3]);
        return 0;
}

int smallest(char* f[1],char* f[2],char* f[3])
{
    int i=1;
        char* pLowest = f[1];
    if(strcmp(pLowest, f[2]) > 0)
                i=2;
      pLowest = f[2];
      if(strcmp(pLowest, f[3]) > 0)
      pLowest = f[3];
          i=3;
      return i;
}

  int equal(char*f1,char*f2,char*f3)
  {
         
    if(strcmp(f1,f3)==0)
        {
      return  1;
        }
    if(strcmp(f2,f3)==0)
        {
      return  2;
        }
          return NULL;
  }

---

Probably because of this:

Code:

---

char* equal(char*f1,char*f2,char*f3);
  int smallest(char*f1,char*f2,char*f3);

---

or rather

Code:

---

int smallest(char* f[1],char* f[2],char* f[3])

---

which I think you want the first version throughout.

i think you meant f1 f2 f3 instead of f[1] f[2] f[3] as you declared in the function on top

also there are a lot of uncasted typeconversions...the compiler is not very happy...check those up too...

but its only a parameter
we can put

Code:

---

int smallest(char* f[1],char* f[2],char* f[3])

---

Code:

---

int smallest(char* bm,char* bjk,char* jjjjj)

---

when i use the function i would write

Code:

---

t=smallest(f[1],f[2],f[3]);

---

it doesnt matter what names i put in the signature
??

it doesnt matter what names i put in the signature
as long as i use them inside the function

Quote:

---

Originally Posted by transgalactic2

it doesnt matter

---

If you say so -- maybe the compiler has a programming problem and should start a new thread about warnings/errors from transgalactic2? ;)

It does matter, dude. You can call the variables different names (or use no name at all) in the prototype but The Types Must Match, and here they do not.

Quote:

---

Originally Posted by transgalactic2

Code:

---

int smallest(char*f1,char*f2,char*f3);

---

Code:

---

int smallest(char* f[1],char* f[2],char* f[3])

---

---

In your forward declaration:
char* f1 is declaring f1, which is a pointer to char.
char* f2 is declaring f2, which is a pointer to char.
char* f3 is declaring f3, which is a pointer to char.

In your function definition:
char* f[1] is declaring f, which is an array of pointers to char.
char* f[2] is also declaring f, which is an array of pointers to char. And
char* f[3] is also declaring f, which is an array of pointers to char.

You are correct that your forward declaration and your function definition do not need to use the same variable names, but they must use the same types. Because you added the brackets [] around the 1, 2 and 3, you changed the types. Remember, a variable name can only contain letters, numbers and the underscore.

like this i get an error too
"Remember, a variable name can only contain letters, numbers and the underscore."
but i get
.c(42) : error C2065: 'c' : undeclared identifier
1>c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : error C2057: expected constant expression
1>c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : error C2466: cannot allocate an array of constant size 0
1>c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : error C2086: 'char **f' : redefinition
1> c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : see declaration of 'f'

Code:

---

int smallest(char* f[a],char* f[b],char* f[c])
{
    int i=1;
        char* pLowest = f[a];
    if(strcmp(pLowest, f[b]) > 0)
                i=2;
      pLowest = f[b];
      if(strcmp(pLowest, f[c]) > 0)
      pLowest = f[c];
          i=3;
      return i;
}

---

It amazes me that even with your long time of asking questions and racking up an impressive 1245 posts doing so, you still haven't fixed your indentation or grasp the very basics.
Of C or posting replies, for that matter.
Pointing out the lines of error may help too.

And posting the entire source.

Quote:

---

Originally Posted by transgalactic2

but i get
.c(42) : error C2065: 'c' : undeclared identifier

Code:

---

int smallest(char* f[a],char* f[b],char* f[c])
{
    int i=1;
        char* pLowest = f[a];
    if(strcmp(pLowest, f[b]) > 0)
                i=2;
      pLowest = f[b];
      if(strcmp(pLowest, f[c]) > 0)
      pLowest = f[c];
          i=3;
      return i;
}

---

---

The compiler doesn't understand that you mean to declare 3 separate variables as arguments to the function. It only sees that you are declaring f 3 times in a row, each time defining it as an array of pointers to char.

Do you understand the difference between these two declarations?

Code:

---

char* f1;
char* f[1];

---

Note that array indexes in C start at 0 not 1.

Quote:

---

Originally Posted by transgalactic2

like this i get an error too
"Remember, a variable name can only contain letters, numbers and the underscore."
but i get
.c(42) : error C2065: 'c' : undeclared identifier
1>c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : error C2057: expected constant expression
1>c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : error C2466: cannot allocate an array of constant size 0
1>c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : error C2086: 'char **f' : redefinition
1> c:\documents and settings\\my documents\visual studio 2005\projects\ex6\ex6\ex6.c(42) : see declaration of 'f'

Code:

---

int smallest(char* f[a],char* f[b],char* f[c])
{
    int i=1;
        char* pLowest = f[a];
    if(strcmp(pLowest, f[b]) > 0)
                i=2;
      pLowest = f[b];
      if(strcmp(pLowest, f[c]) > 0)
      pLowest = f[c];
          i=3;
      return i;
}

---

---

Quote:

---

but i get *errors*

---

you get errors
because "[" and "]" is not a letter,number or underscore(_)
that means what you gave is no longer a variable