Is there a standard C function to do this?

I wrote some code today to accept user input for first and last names and then make sure it's formated as such: Randy Collins

So if the user types RaNDy or rANdY or randy it will format it and then output. My program works fine, but I was wondering if there was a Standard C function I haven't found yet that will do this much easier/faster?

Code:

---

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

int tolower( int c );
int toupper( int c );

int main() {

char FirstName[21];
char LastName[21];
int i, x;

        printf( "Please enter your FIRST name: " );
        scanf( "%[^\n]%*c", FirstName );

        printf( "Please enter your LAST name: " );
        scanf( "%[^\n]%*c", LastName );

                printf( "\nYour full name is: " )

                        for ( i = 0 ; FirstName[i] != 0 ; i = i + 1 ) {
                       
                                for ( x = 0; x < 1; x = x + 1 ) {
                                        printf( "%c", toupper( FirstName[i] ) );
                                i = 1;
                                }

                        printf( "%c", tolower( FirstName[i] ) );
                        }


                        printf(" ");


                        for ( i = 0 ; LastName[i] != 0 ; i = i + 1 ) {

                                for ( x = 0; x < 1; x = x + 1 ) {
                                        printf( "%c", toupper( LastName[i] ) );       
                                i = 1;
                                }
 
                        printf( "%c", tolower( LastName[i] ) );
                        }

return 0;
}

---

No, there's no standard function that does that.

(One comment: There's no reason to do a for-loop from zero to zero. Just call toupper(FirstName[0]).)

Thanks.

Yeah, I guess I was just overthinking it a bit with that for-loop for x. I'll modify the code

Quote:

---

Originally Posted by tabstop

No, there's no standard function that does that.

(One comment: There's no reason to do a for-loop from zero to zero. Just call toupper(FirstName[0]).)

---

What you could do is create your own function that performs the case changing you want, and then you won't have duplicated logic in your program.

Code:

---

char* capitalize( char* str )
{
        int
                cap = 1;
        char*
                ptr = str;
        for( ; *ptr; ++ptr )
        {
                if( !isalpha( *ptr ) )
                        cap = 1;
                else if( cap )
                        *ptr = toupper( *ptr ),
                        cap = 0;
                else
                        *ptr = tolower( *ptr );
        }       
        return str;
}

---

hth.

I was thinking something a bit more compact.

Code:

---

void capitalize( char* str ) {
       
        int i = 1 ;
        if (! *str) return ;  // emtpy string
        str[0] = toupper(str[0]) ;
        while (str[i] ) {
                str[i++] = tolower(str[i]) ;
        }
        return ;
}

---

Quote:

---

Originally Posted by Dino

I was thinking something a bit more compact.

Code:

---

void capitalize( char* str ) {
   
    int i = 1 ;
    if (! *str) return ;  // emtpy string
    str[0] = toupper(str[0]) ;
    while (str[i] ) {
        str[i++] = tolower(str[i]) ;
    }
    return ;
}

---

---

That works too (the empty string check isn't necessary, though), but of course the string couldn't have any leading whitespace. What I posted actually capitalizes all of the "words" in the text, which may not be desirable in some cases (eg: just capitalizing the first word in a sentence), but for the general case, it's a pretty useful approach. For instance, let's say the input is "615 texas ave." - the function would convert that to "615 Texas Ave.", etc.

EDIT:
Whoops, the empty string check is necessary, actually. Sorry.

Here's my 2c:

Code:

---

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

void capitalize(char *name)
{
    for (int i = 0 ; name[i]; ++i)
        printf("%c", i ? tolower(name[i]) : toupper(name[i]));
}

int main()
{
    char FirstName[21];
    char LastName[21];
    int i, x;

    printf( "Please enter your FIRST name: " );
    scanf( "%[^\n]%*c", FirstName );
    printf( "Please enter your LAST name: " );
    scanf( "%[^\n]%*c", LastName );

    printf( "\nYour full name is: " );
    capitalize(FirstName);
    printf(" ");
    capitalize(LastName);
    printf("\n");
}

---

I like your version of code as it seems the most readable to me... However, there are a few parts of one line of code that I don't quite understand. Could you or someone explain this to me?

I'm not sure about the the i ? and :

Code:

---

printf("%c", i ? tolower(name[i]) : toupper(name[i]));

---

It's the ternary operator - basically shorthand for if/else expressions:

Code:

---

char ch;
if(i)
    ch = tolower(name[i]);
else
    ch = toupper(name[i]);
printf("%c", ch);

---

They can be nested as well. For instance:

Code:

---

printf("%c", i > 0 ? tolower(name[i]) : i == 0 ? toupper(name[i]) : '?');
// same as:
char ch;
if(i > 0)
    ch = tolower(name[i]);
else if(ch == 0)
    ch = toupper(name[i]);
else /* i < 0 */
    ch = '?';
printf("%c", ch);

---