Question

Just wondering if someone could explain this to me? I have a program that asks a user to input a sentence. The program then reads the user input into an array and changes all of the vowels to a $ sign. My question is how does the for loop work? When initialising char c = 0; does that not mean that the array element is an int? I can’t understand how it functions.

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

int main(void)
{
char words[50];
char c;

printf("Enter any number of words: \n");
fgets(words, 50, stdin);

    for(c = 0; words[c] != '\n'; c++)
    {
            if(words[c] =='a'||words[c]=='e'||words[c]=='i'||words[c]=='o'||words[c]=='u')
            {
                words[c] = '$';
            }
    }
printf("%s", words);

return 0;
}

Answer 1

The code treats c as an integer variable (in C, char is basically a very narrow integer). In my view it would be cleaner to declare it as int (perhaps unsigned int). However, given that words is at most 50 characters long, char c works fine.

As to the loop:

1. c = 0 initializes c to zero.
2. words[c] != '\n' checks — right at the start and also after each iteration — whether the current character (words[c]) is a newline, and stops if it is.
3. c++ increments c after each iteration.