// WE WILL WRITE OUR OWN STRING HELPER METHODS
// DO NOT IMPORT ADDITIONAL LIBRARIES FOR THIS EXERCISE
#include <stdio.h>
#include <cs50.h>

// TODO: update helper prototypes with parameter and return types
int isAlpha(char txt);
int strLen(string str);
char toUpper(char txt);
string toUpperString(string txt);

int main(void)
{
    // TODO: write tests for each of your methods as you complete them

    printf("output of isAlpha is %i\n", isAlpha('&'));
    printf("output of toUpper is %c\n", toUpper('c'));

    string str = get_string("test string: ");
    printf("length of string is %i\n", strLen(str));
    printf("output of toUpperString is %s\n", toUpperString(str));
}

int isAlpha(char txt)
{
    // return 1 if char variable named txt is an alpha char
    if ((txt >= 'A' && txt <= 'Z') || (txt >= 'a' && txt <= 'z'))
    {
        return 1;
    }
    // can think of this as an implied else
    return 0;
}

int strLen(string str)
{
    // count chars until we find '\0' special char
    int len = 0;
    while (str[len] != '\0'){
        len++;
    }
    return len;
}

int strLenFor(string str)
{
    // count chars until we find '\0' special char
    int len = 0;
    for (int i = 0; str[i] != '\0'; i++){
        len = i;
    }

    // len has scope within the entire function, i has scope only within the for loop
    return len + 1;
}

char toUpper(char txt)
{
    // return 1 if char variable named txt is an alpha char
    if (txt >= 'a' && txt <= 'z')
    {
        return txt - ('a' - 'A');
    }
    // can think of this as an implied else
    return txt;
}

string toUpperString(string txt)
{
    // declare new string to store updated values
    for (int i = 0; i < strLen(txt); i++)
    {
        // use our new helper method!
        txt[i] = toUpper(txt[i]);
    }
    return txt;
}