Thread: parameter names without types and conflicting types in fgets

I have this code:

Code:

#include<stdio.h>
#include<ctype.h>
#include<string.h>


int check_up(char string[]);
int check_low(char string[]);
void to_up(char string[]);
void to_low(char string[]);


int main()
{    char word[1];
    printf("Input a string:");
    fgets(word, sizeof(word), stdin);
    int up, low;
    
    up= check_up(word);
    low= check_low(word);
        
    if( (up==0) && (low ==0)){
        printf("%s is neither all uppercase nor all lowercase.\n", word);        
    }else if( low==1){
        printf("%s is all lowercase.\n", word);
    }else if( up==1)
        printf("%s is all uppercase.\n", word);
    }
    
    to_up(word);
    printf("All uppercase %s.\n", word);
    to_low(word);
    printf("All lowercase %s.\n", word);
    
    return 0;
}
//Check if all upper
int allupper(char string[]){
    int a;
    a = 0;
    if ( string[a] == '\n' )
        {
            string[a] = '\0'; 
        }    
    isupper(string[a]);
}
//Check if all lower
int alllower(char string[]){
    int a;
    a = 0;
    if ( string[a] == '\n' )
        {
            string[a] = '\0'; 
        }    
    islower(string[a]);
}
//Converts to lower
void to_low(char string[]){ 
    int a;
    a = 0;
    if ( string[a] == '\n' )
        {
            string[a] = '\0'; 
        }
     string[a] = tolower(string[a]);
}
//Converts to upper
void to_up(char string[]) {    
    int a;
         a = 0;
    if ( string[a] == '\n' )
        {
            string[a] = '\0'; 
        }
    string[a] = tolower(string[a]);
}

When I compile this I have the following problems:

• warning: data definition has no type or storage class [enabled by default] in 'to_up(word)'
• conflicting types in 'to_up' function and to_low function
• warning: data definition has no type or storage class [enabled by default] into_up function
• error: unknown type name ‘word’ in line 'printf("All uppercase %s.\n", word):;'
• warning: parameter names (without types) in function declaration [enabled by default] in 'to_up(word)'and 'to_low(word)'
  
• 'note: previous declaration of ‘to_up’ was here in function declaration of to_up function

How I can fix this problems?

You have a close-curly-brace on line 27 (of what's posted here) that doesn't match any open-curly-brace. (Or more to the point, as far as the compiler is concerned it matches the open curly brace on line 13, which means you have a lot of code that no longer lives in a function.)
Using actual indentation, and better yet, watching when your editor indents things in a way that doesn't match what you want, would really help you spot this sort of thing.

Assuming the line numbers haven't changed, then line 44 is

Code:

 isupper(string[a]);

which is exactly what the warning says: a statement with no effect. isupper just returns true/false. If you want to do something with that information, then ... well, you should do something with it as opposed to currently, where you are just having it sit there and not do anything.

Well, a two-byte string can hold exactly one letter in it (one byte is reserved for the end-of-string marker). If you want more letters, you need a bigger string.

Also, none of your functions work with anything other than the first letter -- you are always starting with a = 0, but it never changes as you go. You probably want loops.

Code:

if( (up==0) && (low ==0)){
		printf("%s is neither all uppercase nor all lowercase.\n", word);		
	}else if( low==1){
		printf("%s is all lowercase.\n", word);
	}else if( up==1){
		printf("%s is all uppercase.\n", word);
	}

int check_up(char string[]){
	int a,b;
	a = 0;
	while( (string[a] != '\0') && (string[a] != '\n'))
        {	b= isupper(string[a]);
			a++;			
			if(a>SIZE)
				break;
        }
	if(b != 0)
		b=1;	
	return b;

If my input is NMB48 it is supposed to display that NMB48 is uppercase, but it says it is neither.

Why should NMB48 be all uppercase? Neither 4 nor 8 is an uppercase letter.

(If you want to exclude non-letters, then you need to check isalpha before you check isupper.)