Java Do-While Loop

The do-while loop in Java is a control flow statement that enables the repeated execution of code based on a specified boolean condition. Unlike the standard while loop, the do-while loop ensures that the code block executes at least once before the condition is evaluated.

Key Concepts

• Execution Flow:
  1. The code block inside the do is executed first.
  2. After execution, the condition is evaluated.
  3. If the condition is true, the loop continues, executing the code block again.
  4. If the condition is false, the loop terminates.
• Key Points:
  • The loop checks the condition after executing the code block.
  • This guarantees at least one execution of the code block.
  • It is particularly useful when the initial execution of the loop is necessary prior to condition verification.

Syntax:

do {
    // code block to be executed
} while (condition);

Example

Below is a simple example to demonstrate the do-while loop:

public class DoWhileExample {
    public static void main(String[] args) {
        int count = 0;
        
do {
            System.out.println("Count is: " + count);
            count++;
        } while (count < 5);
    }
}

Explanation of the Example:

• The loop initiates with count set to 0.
• Within the do block, the current value of count is printed.
• count is then incremented by 1.
• The condition count < 5 is checked after the first iteration.
• The loop continues until count reaches 5, resulting in the values 0 to 4 being printed.

Conclusion

The do-while loop is a valuable construct in Java for scenarios where it is essential to ensure that a block of code runs at least once. A solid understanding of its structure and behavior is crucial for effective programming in Java.