c_cpp 第1周续：Vigen1 - 检查字母键的功能

Posted 2021-05-14

#include <stdio.h>
#include <string.h>
#include <cs50.h>
#include <ctype.h>

bool check_alpha(string k);

// this code is to check if the function for checking if it's an alphabetical key string works or not

int main(int argc, string argv[])
{
	if (argc != 1)
	{
		// get key from command line argument
			string key = argv[(argc - 1)];

		// check if the key string is alphabetical
			bool y = check_alpha(key);

			if ( y )
			{
				printf("The key string is alphabetical.\n");
			}
			else
			{
				printf("The key string is not alphabetical.\n");
			}


	}
}

bool check_alpha(string k)
{
	int l=strlen(k);
	int i=0;
	while ( (k[i] != '\0') && (isalpha(k[i])) )
	{
		i++;
	}
	if ( i == l )
	{
		return true;
	}
	else
	{
		return false;
	}
}