Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

6.6.1 Count Characters in a Line
Chapter 6 ■ Characters
Suppose we want to count the number of characters in a line of input. Now we must read
characters until the end of the line. How does our program test for end-of-line? Recall that when
the “Enter” or “Return” key is pressed by the user, the newline character, \n, is returned by
getchar. The following while condition reads a character and tests for \n.
while ((ch = getchar()) != '\n')
Program P6.6 reads a line of input and counts the number of characters in it, not counting the
“end-of-line” character.
Program P6.6
//count the number of characters in the input line
#include <stdio.h>
int main() {
char ch;
int numChars = 0;
printf("Type some data and press 'Enter' \n");
while ((ch = getchar()) != '\n') // repeat as long as ch is not \n
numChars++;
// add 1 to numChars
}
printf("The number of characters is %d \n", numChars);
The main difference between this and Program P6.5 is that this one reads characters until the end
of the line rather than until the first non-blank. A sample run is:
Type some data and press 'Enter'
One moment in time
The number of characters is 18
6.7 Count Blanks in a Line of Data
Suppose we want to count all the blanks in a line of data. We must still read characters until
the end of the line is encountered. But now, for each character read, we must check whether
it is a blank. If it is, the count is incremented. We would need two counters—one to count the
153
www.it-ebooks.info