Count Words in String C Program

Count Words in String C Program – Write down a C program to input a string and find the number of words in it.

Count words in string C Programming

Source Code

#include <stdio.h>

void main()
{
    char str[100];
    int wordcount=1, i=0;

    printf("Enter a string to count No. of words :\n");
    fgets(str, 100, stdin);   

    while(str[i]!='\0')        
    {
        if(str[i]==' ' || str[i]=='\n' || str[i]=='\t')
            wordcount++;
        i++;
    }

    printf("Total number of words in the string: %d", wordcount-1);
}

Output

Enter a string to count No. of words :
Easy Code Book
Total number of words in the string: 3

Line by Line Explanation of Source Code

Let’s go through the code step by step and explain each part along with a sample output using the string “Hello World of C Programming”:

Explanation:

1. The code begins with the inclusion of the standard input/output library stdio.h, which provides functions for input and output operations.
2. The main function is defined, which is the entry point of the program.
3. Inside the main function, several variables are declared.
   • char str[100] is an array of characters that will hold the input string.
   • int wordcount is an integer variable that will store the count of words in the string.
   • int i is an integer variable used as an index for iterating through the characters of the string.
4. The printf function is used to display the prompt message to the user: “Enter a string to count No. of words :”.
5. The fgets function is used to read a line of input from the user. It takes three arguments:
   • str is the destination buffer where the input will be stored.
   • 100 is the maximum number of characters to be read (including the null character).
   • stdin is the standard input stream from which the input is read (in this case, it’s the keyboard).

   Sample output:

   Enter a string to count No. of words :
Hello World of C Programming

6. The program enters a while loop that iterates over each character in the string until it encounters the null character '\0', which marks the end of the string.
7. Inside the loop, there is an if condition that checks if the current character str[i] is a space ' ', newline '\n', or tab '\t'. If any of these characters are found, it means a word boundary has been reached, so the wordcount is incremented.
8. After the if condition, the index variable i is incremented to move to the next character in the string.
9. Once the loop finishes, the total number of words is calculated by subtracting 1 from wordcount (since we initially set it to 1). This is done to account for the fact that the last word doesn’t have a word boundary character after it.
10. Finally, the printf function is used to display the total number of words in the string. The value of wordcount-1 is substituted in the format string, and the result is printed.

Sample output:

In the given example, the output is 5, which represents the number of words in the string “Hello World of C Programming.”