Write a C program to calculate the average word length of a sentence using while loop

In C programming, calculating the average word length of a sentence involves counting the total characters (excluding spaces) and dividing by the number of words. This program demonstrates how to use a while loop to process user input character by character and calculate the average word length.

Syntax

while(condition) {
    // Process each character
    // Count characters and words
}

Algorithm

1. Read the sentence character by character using a while loop
2. Count total characters (excluding spaces) and words
3. Calculate average by dividing character count by word count
4. Return the average as a double value

Example: Calculate Average Word Length

This program reads a sentence and calculates the average length of words using a while loop −

#include <stdio.h>

double calculateWordLength(const char *stmt) {
    int charCount = 0;
    int wordCount = 1;
    
    while (*stmt != '
' && *stmt != '\0') {
        if (*stmt != ' ') {
            charCount++;
        } else if (*stmt == ' ') {
            wordCount++;
        }
        stmt++;
    }
    
    return (double)charCount / wordCount;
}

int main() {
    char stmt[100];
    int i = 0;
    double avgLen;
    
    printf("Enter a sentence: ");
    
    while ((stmt[i] = getchar()) != '
') {
        i++;
    }
    stmt[i] = '\0';
    
    avgLen = calculateWordLength(stmt);
    printf("Average word length: %.2f
", avgLen);
    
    return 0;
}

Enter a sentence: Tutorials Point is the best resource
Average word length: 5.17

How It Works

• The main function reads input character by character using getchar() in a while loop
• The calculateWordLength() function processes each character to count letters and words
• Non-space characters increment charCount
• Space characters increment wordCount
• The average is calculated as (double)charCount / wordCount

Key Points

• The while loop continues until a newline character is encountered
• Word count starts at 1 to account for the last word (no trailing space)
• Type casting to double ensures floating-point division
• The program handles sentences with multiple spaces correctly

Conclusion

This program effectively demonstrates using while loops for character-by-character processing in C. The average word length calculation provides useful text analysis functionality with proper handling of spaces and word boundaries.