Question

My task is to check the user input and replace each period with exclamation mark, and each exclamation mark with 2 exclamation marks, then count the number of substitutions made.

This is my code:

int main(void)

{

    int userInput, substitutionsNum = 0;

    printf("please enter your input:\n");
    while ((userInput = getchar()) != '#')
    {
        if (userInput == '.')
        {
            userInput = '!';
            ++substitutionsNum;
        }

        else if (userInput == '!')
        {
            userInput = '!!';
            ++substitutionsNum;
        }
    }

    printf("%c, the number of substitutions are: %d", userInput, substitutionsNum);
    return 0;
}

If I put in the input “nir.” and then “#” to go out of the program, the output is “#, the number of substitutions are: 1”

Answer 1

You never print the input back out except once at the end, so the “replacement” won’t work.

Also, you can’t represent a pair of exclamation points as '!!', that’s a multi-character literal which is not the same. At least, no I/O functions will do what you expect with it, if you try to print it for instance.