Question

You will implement some helpful string functions. The prototypes are below. The only built-in functions you can use are toupper() and tolower() – found in ctype.h.

char* capitalize(char* s);
char* str2Lwr(char* s);
char* str2Upr(char* s);

All of the functions should be "in-place". In-place means that you should update the string pointed to by s, rather than creating a new one.

capitalize() should convert the first character of string s to upper case. The value of s is returned.

str2Lwr() should convert the entire string s to lower case. The value of s is returned.

str2Upr() should convert the entire string s to upper case. The value of s is returned.

If the character to be converted does not have a "case", mimic the tolower() and toupper() functions.

In main, define and initialize strings to test your functions. Call your functions with the strings you initialized to verify the functions are implemented correctly.

Answer 1

C++ program:

StringCaseConversion.cpp:

#include <iostream>
#include <string.h>
using namespace std;

char* capitalize(char* s)
{
    s[0]=toupper(s[0]);//capitalizes the first letter in string
    return s;
}
char* str2Lwr(char* s)
{
    int i=0;
    for(i=0; i<strlen(s); i++)
        s[i] = tolower(s[i]);//takes the string char by char and converts to lower case
    return s;
}
char* str2Upr(char* s)
{
    int i=0;
    for(i=0; i<strlen(s); i++)
        s[i] = toupper(s[i]);//takes the string char by char and converts to upper case
    return s;
}
int main() {
    char *x = strdup("shyam");
    char *y = strdup("cheGG");
    char *z = strdup("c++");
    char *a = strdup("prograM");

    cout<<"Capitalizing the words: ";
    cout<<endl;
    cout<<capitalize(x)<<endl;
    cout<<capitalize(y)<<endl;
    cout<<capitalize(z)<<endl;
    cout<<capitalize(a)<<endl;
    cout<<endl<<endl;
    cout<<"Converting all letters to lower case";
    cout<<endl;

    cout<<str2Lwr(x)<<endl;
    cout<<str2Lwr(y)<<endl;
    cout<<str2Lwr(z)<<endl;
    cout<<str2Lwr(a)<<endl;
    cout<<endl<<endl;

    cout<<"Converting all letters to UPPER case";
    cout<<endl;
    cout<<str2Upr(x)<<endl;
    cout<<str2Upr(y)<<endl;
    cout<<str2Upr(z)<<endl;
    cout<<str2Upr(a)<<endl;
}

Output: