Incompatible Type Error

Question

main()
{
FILE *fin;
char line[50];
char exp[SIZE];
fin=fopen("prefix.txt","r");

if(fin==NULL)
{
     printf("\nFile Cannot be Opened\n");              
}
else
{
        printf("\nfile opened\n");

       while(fgets(line, sizeof(line), fin)!=NULL)
       {
              sscanf(line, "%s", exp);

              exp=delete_spaces(exp);
       }    
}
fclose(fin);
getch();   
}

char delete_spaces(char a[])
{
   int l,k=0,i=0;
   l=strlen(a);

   while(i<l)
   {
        if(a[i]==' ')
        i++ 
        else
        a[k++]=a[i++];    
   } 
   return a;    
}

After compiling this program I am getting error "Compatibility Type Error" In line containing "exp=delete_spaces(exp);" and I don't know how to remove it. Is there is some problem with array passing ?

Answer 1

Here you are passing the array address to delete_spaces(char a[]) in call delete_spaces(exp) so you dont need to take the return value and assign back as

exp=delete_spaces(exp);

instead change function defination to,

void delete_spaces(char a[]);

and function call to

delete_spaces(exp);

And also put the definition or prototype of function before main(). And remove the return statement from delete_spaces() definition.

and the code for delete_spaces() will be

void delete_spaces( char a[])
{
    int l,k=0,i=0;
   l=strlen(a);

   while(i<l)
   {
        if(a[i]==' ')
        i++; 
        else
        a[k++]=a[i++];    
   } 
   a[k]='\0';
}