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Java do-while loop

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🎢 Java Do-While Loop: The "At Least Once" Ride! 🎡​

Ever wanted a loop that guarantees at least one execution, no matter what? Well, say hello to the do-while loop—the thrill ride of Java loops! 🎠 Unlike its cautious cousin, the while loop, the do-while loop dives straight in and only checks if it should continue after the first run. 🚀

🧐 The "Must-Know" Syntax​

Here’s how you write a do-while loop:

do {
    // Execute this block at least once
} while (condition);

Key Takeaways 📝​

  • The loop always runs at least once—no ifs, ands, or buts! 🙌
  • The condition is checked after execution, unlike a while loop.
  • Don't forget the semicolon ( ; ) after while (condition); or Java will give you the "silent treatment" (a.k.a. errors 😅).
  • Can be exited early with a break statement if needed.

🏁 Example: Counting from 1 to 5​

Here’s a simple example of a do-while loop in action:

int i = 1;
do {
    System.out.println(i);
    i++;
} while (i <= 5);

Output:

1
2
3
4
5

Even if i started at 6, the loop would still print 6 once before checking the condition! 🤯

🥊 Do-While vs While: The Showdown​

What’s the real difference between while and do-while loops? Let's compare:

int i = -10;

// Simple while loop
while (i > 0) {
    System.out.println(i);  // Does not print anything!
    i++;
}

// Do-while loop

do {
    System.out.println(i);  // Prints -10 and THEN exits!
    i++;
} while (i > 0);

Key Difference 🎯​

  • while: Checks before executing → Might never run ❌
  • do-while: Checks after executing → Runs at least once ✅

🚨 Watch Out for Infinite Loops! 🚨​

If you forget to update your condition inside the loop, you might end up in an infinite loop. Like this... 😱

do {
    System.out.println("This will never end... send help! 😵");
} while (true); // No exit condition!

Make sure to modify your condition variable inside the loop, or you’ll be staring at your terminal forever. 😂

🎉 Final Thoughts​

The do-while loop is perfect when you need to execute a block at least once, regardless of the condition. It's especially useful for: ✅ Menus that should display at least once 📜 ✅ User input validation loops ⌨️ ✅ Cases where checking conditions before execution doesn’t make sense 🤔

Now go forth and loop responsibly! 💻🔥

** Happy Coding! 🚀**