C Program to Print Numbers Till 5 using do-while Loop

Understanding the do-while Loop

• Exit-controlled loop: The do-while loop first executes the code block within the loop, and then checks the condition.
• Guaranteed execution: This means the code block will always execute at least once, even if the condition is initially false.

Code Structure and Explanation

C

#include <stdio.h>

int main() {
    int i = 1;  // Initialize the counter variable

    do {
        printf("%d ", i);  // Print the current value of i
        i++;  // Increment the counter for the next iteration
    } while (i <= 5);  // Check the condition (loop continues if i is less than or equal to 5)

    return 0;
}

Explanation:

1. Header Inclusion: #include <stdio.h> provides input/output functions like printf.
2. Main Function: The program execution begins in the main function.
3. Variable Declaration: int i = 1; declares and initializes the counter variable i to 1.
4. do-while Loop:
   • The do block executes first, printing the current value of i and then incrementing it.
   • The while condition i <= 5 checks if i is still within the range (less than or equal to 5).
   • If the condition is true, the loop repeats, printing the next number.
5. Loop Termination: The loop continues as long as i is less than or equal to 5. Once i becomes 6, the condition becomes false and the loop terminates.
6. Return Statement: return 0; indicates successful program termination.

Output:

1 2 3 4 5

Key Points:

• The do-while loop is useful when you need the code block to execute at least once, regardless of the condition.
• The condition is checked at the end of the loop, ensuring at least one iteration.
• Other loop types like for and while may be more suitable in different scenarios, depending on the specific requirements.