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Program to find the First Capital Letter in a String using Recursion

Program to find the First Capital Letter in a String using Recursion

The following C program, using recursion, finds the first capital letter that exists in a string. We have included ctype.h in order to make use of "int isupper(char);" function that's defined inside the ctype.h headerfile. The isupper finction returns 1 if the passed character is an uppercase and returns 0 is the passed character is a lowercase.

    #include <stdio.h>

    #include <string.h>

    #include <ctype.h>

    char caps_check(char *);

    int main()

    {

        char string[25], letter;

        printf("Enter a string to find it's first capital letter: ");

        scanf("%s", string);

        letter = caps_check(string);

        if (letter == 0)

        {

            printf("No capital letter is present in %s.\n", string);

        }

        else

        {

            printf("The first capital letter in %s is %c.\n", string, letter);    }

            return 0;

        }

        char caps_check(char *string)

        {

            static int j = 0;

            if (j < strlen(string))

            {

                if (isupper(string[j]))

                {

                    return string[j];

                }

                else

                {

                    j = j + 1;

                    return caps_check(string);

                }

            }

            else return 0;

        }