Lesson 12: While Loops - Master Condition-Based Loops

🎯 သင် သင်ယူမည့် အရာများ

ဒီ lesson မှာ သင် သင်ယူမည့် အရာများ:

While loop ဆိုတာ ဘာလဲ၊ ဘယ်အခါ သုံးရမလဲ
While loop syntax နဲ့ အလုပ်လုပ်ပုံ
While vs For loops - ဘယ်အချိန် ဘာသုံးရမလဲ
Do-While loop - အနည်းဆုံး တစ်ကြိမ် run ရမယ့် loop
Infinite loops - ဘာကြောင့် ဖြစ်လဲ၊ ဘယ်လို ရှောင်ရမလဲ
Loop control statements (break & continue)
Input validation နဲ့ menu systems
Real-world practical examples

📖 While Loop ဆိုတာ ဘာလဲ?

While loop ဆိုတာ condition true ဖြစ်သရွေ့ code block ကို ထပ်ခါထပ်ခါ execute လုပ်တဲ့ loop တစ်မျိုးပါ။ For loop လို iterations အရေအတွက် သိစရာ မလိုဘူး - condition false ဖြစ်တဲ့အထိ run နေမယ်။

နေ့စဉ်ဘဝမှာ ဥပမာများ:

မိုးရွာနေသရွေ့ အိမ်မှာ နေပါ (condition: မိုးရွာနေတာ)
လမ်း ရှင်းနေသရွေ့ မောင်းပါ (condition: လမ်းရှင်းတာ)
Password မှားနေသရွေ့ ထပ်မေးပါ (condition: password မှန်/မမှန်)
Balance မလုံလောက်သရွေ့ ငွေထုတ်လို့ မရဘူး (condition: balance check)

အဲ့ဒီလို scenarios တွေမှာ while loop က perfect!

For vs While - အဓိက ခြားနားချက်

Aspect	For Loop	While Loop
အသုံးပြုရန်	Iterations သိချင်တဲ့အခါ	Condition အပေါ် မူတည်တဲ့အခါ
Structure	for (init; condition; increment)	while (condition)
Best for	Arrays, counting, known iterations	User input, validation, unknown iterations
Example	Print 1 to 100	Keep asking until password correct

🔹 Basic While Loop Syntax

While loop ရဲ့ basic structure:

Java

while (condition) {
    // condition က true ဖြစ်သရွေ့ run မယ်
    statements;
    // condition ကို update လုပ်ဖို့ မမေ့ပါနဲ့!
}

အရေးကြီးတဲ့ အချက်များ:

Condition check: Loop body run မီ condition ကို စစ်တယ် (pre-check)
Update variable: Loop body ထဲမှာ condition ကို update လုပ်ရမယ် (infinite loop ဖြစ်မှာ မဟုတ်ရင်)
Zero iterations: Initial condition က false ဆိုရင် တစ်ကြိမ်မှ မ run ဘူး
Boolean condition: Condition က boolean expression ဖြစ်ရမယ် (true/false)

Flow Chart

1. Check condition → true?
   ├─ Yes: Execute loop body
   │         ↓
   │   Update variables
   │         ↓
   │   Go back to step 1
   │
   └─ No: Exit loop, continue program

🔹 Simple Example: Count to 10

While loop နဲ့ 1 ကနေ 10 အထိ ရေတွက်ခြင်း:

Java

public class WhileCount {
    public static void main(String[] args) {
        int i = 1;  // Initialize
        
        while (i <= 10) {  // Condition
            System.out.println(i);
            i++;  // Update (အရေးကြီး!)
        }
        
        System.out.println("Done!");
    }
}

Output:

For loop နဲ့ နှိုင်းယှဉ်ရင်:

// While loop
int i = 1;
while (i <= 10) {
    System.out.println(i);
    i++;
}

// For loop (same result)
for (int i = 1; i <= 10; i++) {
    System.out.println(i);
}

// For loop က တိုပြီး clean ပိုဖြစ်တယ် known iterations အတွက်!

🔹 Input Validation - While Loop ရဲ့ အင်အား!

User က valid input မထည့်သမျှ ထပ်မေးဖို့ while loop က perfect:

Example 1: Password Validation

Java

import java.util.Scanner;

public class PasswordCheck {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String correctPassword = "java123";
        String userInput = "";
        int attempts = 0;
        int maxAttempts = 3;
        
        System.out.println("=== Password Login System ===");
        
        while (!userInput.equals(correctPassword) && attempts < maxAttempts) {
            System.out.print("Enter password: ");
            userInput = scanner.nextLine();
            attempts++;
            
            if (!userInput.equals(correctPassword)) {
                int remaining = maxAttempts - attempts;
                if (remaining > 0) {
                    System.out.println("❌ Wrong password! " + remaining + " attempts left.");
                } else {
                    System.out.println("❌ Account locked! Too many failed attempts.");
                }
            }
        }
        
        if (userInput.equals(correctPassword)) {
            System.out.println("✓ Login successful! Welcome!");
        }
        
        scanner.close();
    }
}

Sample Output:

=== Password Login System ===
Enter password: abc123
❌ Wrong password! 2 attempts left.
Enter password: test
❌ Wrong password! 1 attempts left.
Enter password: java123
✓ Login successful! Welcome!

Example 2: Age Validation

Java

import java.util.Scanner;

public class AgeValidation {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int age = -1;  // Invalid initial value
        
        System.out.println("Enter your age (1-120):");
        
        while (age < 1 || age > 120) {
            System.out.print("Age: ");
            
            if (scanner.hasNextInt()) {
                age = scanner.nextInt();
                
                if (age < 1 || age > 120) {
                    System.out.println("Invalid age! Please enter between 1 and 120.");
                }
            } else {
                System.out.println("Please enter a valid number!");
                scanner.next();  // Clear invalid input
            }
        }
        
        System.out.println("Thank you! Your age: " + age);
        scanner.close();
    }
}

🔹 Menu-Driven Programs

Menu systems မှာ while loop က အရမ်း သုံးတယ် - user က exit မရွေးမချင်း ထပ်ခါထပ်ခါ menu ပြနေတယ်:

Java

import java.util.Scanner;

public class CalculatorMenu {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int choice = 0;
        
        while (choice != 5) {
            System.out.println("\n=== Simple Calculator ===");
            System.out.println("1. Addition");
            System.out.println("2. Subtraction");
            System.out.println("3. Multiplication");
            System.out.println("4. Division");
            System.out.println("5. Exit");
            System.out.print("Enter choice (1-5): ");
            
            choice = scanner.nextInt();
            
            if (choice >= 1 && choice <= 4) {
                System.out.print("Enter first number: ");
                double num1 = scanner.nextDouble();
                System.out.print("Enter second number: ");
                double num2 = scanner.nextDouble();
                double result = 0;
                
                switch (choice) {
                    case 1:
                        result = num1 + num2;
                        System.out.println("Result: " + num1 + " + " + num2 + " = " + result);
                        break;
                    case 2:
                        result = num1 - num2;
                        System.out.println("Result: " + num1 + " - " + num2 + " = " + result);
                        break;
                    case 3:
                        result = num1 * num2;
                        System.out.println("Result: " + num1 + " × " + num2 + " = " + result);
                        break;
                    case 4:
                        if (num2 != 0) {
                            result = num1 / num2;
                            System.out.println("Result: " + num1 + " ÷ " + num2 + " = " + result);
                        } else {
                            System.out.println("Error: Cannot divide by zero!");
                        }
                        break;
                }
            } else if (choice == 5) {
                System.out.println("Thank you for using calculator! Goodbye!");
            } else {
                System.out.println("Invalid choice! Please select 1-5.");
            }
        }
        
        scanner.close();
    }
}

Sample Output:

=== Simple Calculator ===
1. Addition
2. Subtraction
3. Multiplication
4. Division
5. Exit
Enter choice (1-5): 1
Enter first number: 10
Enter second number: 5
Result: 10.0 + 5.0 = 15.0

=== Simple Calculator ===
1. Addition
...
Enter choice (1-5): 5
Thank you for using calculator! Goodbye!

🔹 Do-While Loop

Do-while loop က while loop နဲ့ ဆင်တယ်၊ ဒါပေမယ့် condition ကို အဆုံးမှာ စစ်တယ်။ ဆိုလိုတာက အနည်းဆုံး တစ်ကြိမ် run မယ်!

Java Syntax

do {
    // Code ကို အရင် run တယ်
    statements;
} while (condition);  // နောက်မှ condition စစ်တယ်

While vs Do-While:

While: Condition အရင်စစ် → true ဖြစ်မှ run (0 or more times)
Do-While: အရင် run → နောက် condition စစ် (1 or more times)

Example: Menu (Must Show At Least Once)

Java

import java.util.Scanner;

public class DoWhileMenu {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String response;
        
        do {
            System.out.println("\n=== Welcome to Our Service ===");
            System.out.println("We're here to help you!");
            System.out.println("Have a great day!");
            
            System.out.print("\nDo you want to see this again? (yes/no): ");
            response = scanner.nextLine().toLowerCase();
            
        } while (response.equals("yes"));
        
        System.out.println("Goodbye!");
        scanner.close();
    }
}

Comparison Example

Java

// While loop
int x = 10;
while (x < 5) {
    System.out.println("This never prints!");  // ဘာမှ မထွက်ဘူး
}

// Do-While loop
int y = 10;
do {
    System.out.println("This prints once!");  // တစ်ကြိမ် ထွက်တယ်
} while (y < 5);

🔹 Infinite Loops - အန္တရာယ်!

Infinite loop ဆိုတာ condition က ဘယ်တော့မှ false မဖြစ်လို့ loop က အဆုံးမရှိ run နေတဲ့ အခြေအနေပါ:

❌ Common Infinite Loop Mistakes

WRONG!

// Mistake 1: Forgot to update
int i = 1;
while (i <= 10) {
    System.out.println(i);
    // i++ ထည့်ဖို့ မေ့သွားတယ်!
}

// Mistake 2: Wrong update direction
int j = 1;
while (j <= 10) {
    System.out.println(j);
    j--;  // Decreasing instead of increasing!
}

// Mistake 3: Always true condition
while (true) {
    System.out.println("Forever!");
    // No break statement!
}

// Mistake 4: Wrong comparison
int count = 0;
while (count != 10) {
    System.out.println(count);
    count += 2;  // 0,2,4,6,8,10,12... ဘယ်တော့မှ 10 မတူဘူး!
}

✅ How to Avoid Infinite Loops

Always update: Loop variable ကို loop body ထဲမှာ update လုပ်ပါ
Check direction: Increment/decrement က condition နဲ့ ညီရမယ်
Use break: Intentional infinite loop မှာ break condition ထည့်ပါ
Test carefully: Small values နဲ့ test လုပ်ပါ (100 အစား 5)
Add counter: Safety counter ထည့်ပြီး maximum iterations limit လုပ်ပါ

Intentional Infinite Loop (With Break)

Java - Correct Usage

import java.util.Scanner;

public class ServerSimulation {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        // Server က ပိတ်ဖို့ command မရသမျှ run နေမယ်
        while (true) {
            System.out.print("Server> ");
            String command = scanner.nextLine();
            
            if (command.equals("exit")) {
                System.out.println("Shutting down server...");
                break;  // Exit the infinite loop
            }
            
            System.out.println("Processing: " + command);
        }
        
        scanner.close();
    }
}

🔹 Loop Control: Break & Continue

Break Statement

Loop ကနေ ချက်ချင်း ထွက်ဖို့:

Java

// Example: Find first even number
int[] numbers = {1, 3, 5, 7, 8, 9, 11};
int i = 0;

while (i < numbers.length) {
    if (numbers[i] % 2 == 0) {
        System.out.println("First even number: " + numbers[i]);
        break;  // Found it, exit loop
    }
    i++;
}

// Output: First even number: 8

Continue Statement

Current iteration ကို skip လုပ်ပြီး next iteration သွားဖို့:

Java

// Example: Print only odd numbers
int i = 1;

while (i <= 10) {
    if (i % 2 == 0) {
        i++;
        continue;  // Skip even numbers
    }
    
    System.out.println(i);  // Only odd numbers print
    i++;
}

// Output: 1, 3, 5, 7, 9

Break vs Continue:

break: Loop ကနေ လုံးဝထွက်သွားတယ်
continue: Current iteration ကို skip လုပ်ပြီး next iteration ကို ဆက်လုပ်တယ်

💻 Complete Example: Number Guessing Game

While loop, break, continue အားလုံး ပေါင်းစပ်ထားတဲ့ complete game:

Java

import java.util.Scanner;
import java.util.Random;

public class NumberGuessingGame {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Random random = new Random();
        
        System.out.println("=== Number Guessing Game ===");
        System.out.println("I'm thinking of a number between 1 and 100.");
        
        int targetNumber = random.nextInt(100) + 1;
        int attempts = 0;
        int maxAttempts = 7;
        boolean hasWon = false;
        
        while (attempts < maxAttempts) {
            int remaining = maxAttempts - attempts;
            System.out.println("\nAttempts remaining: " + remaining);
            System.out.print("Enter your guess: ");
            
            // Input validation
            if (!scanner.hasNextInt()) {
                System.out.println("❌ Invalid input! Please enter a number.");
                scanner.next();  // Clear bad input
                continue;  // Skip this iteration
            }
            
            int guess = scanner.nextInt();
            attempts++;
            
            // Check if out of range
            if (guess < 1 || guess > 100) {
                System.out.println("❌ Please guess between 1 and 100!");
                attempts--;  // Don't count this attempt
                continue;
            }
            
            // Check the guess
            if (guess == targetNumber) {
                hasWon = true;
                System.out.println("\n🎉 Congratulations! You won!");
                System.out.println("The number was: " + targetNumber);
                System.out.println("You guessed it in " + attempts + " attempts!");
                break;  // Exit the loop
                
            } else if (guess < targetNumber) {
                int difference = targetNumber - guess;
                
                if (difference <= 5) {
                    System.out.println("🔥 Very close! Too low!");
                } else if (difference <= 15) {
                    System.out.println("📈 Too low!");
                } else {
                    System.out.println("⬆️ Way too low!");
                }
                
            } else {
                int difference = guess - targetNumber;
                
                if (difference <= 5) {
                    System.out.println("🔥 Very close! Too high!");
                } else if (difference <= 15) {
                    System.out.println("📉 Too high!");
                } else {
                    System.out.println("⬇️ Way too high!");
                }
            }
        }
        
        if (!hasWon) {
            System.out.println("\n😢 Game Over! You ran out of attempts.");
            System.out.println("The number was: " + targetNumber);
        }
        
        System.out.println("\nThanks for playing!");
        scanner.close();
    }
}

Sample Output:

=== Number Guessing Game ===
I'm thinking of a number between 1 and 100.

Attempts remaining: 7
Enter your guess: 50
📉 Too high!

Attempts remaining: 6
Enter your guess: 25
📈 Too low!

Attempts remaining: 5
Enter your guess: 37
🔥 Very close! Too low!

Attempts remaining: 4
Enter your guess: 40
🎉 Congratulations! You won!
The number was: 40
You guessed it in 4 attempts!

Thanks for playing!

💻 Advanced Example: ATM Banking System

Real-world scenario - ATM machine simulation:

Java

import java.util.Scanner;

public class ATMSystem {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        // Account data
        String accountName = "Aung Aung";
        int pin = 1234;
        double balance = 50000;
        boolean isAuthenticated = false;
        int loginAttempts = 0;
        int maxLoginAttempts = 3;
        
        System.out.println("=== Welcome to A Coder Bank ATM ===");
        
        // PIN verification
        while (!isAuthenticated && loginAttempts < maxLoginAttempts) {
            System.out.print("Enter your PIN: ");
            int userPin = scanner.nextInt();
            loginAttempts++;
            
            if (userPin == pin) {
                isAuthenticated = true;
                System.out.println("✓ Login successful!");
            } else {
                int remaining = maxLoginAttempts - loginAttempts;
                if (remaining > 0) {
                    System.out.println("❌ Incorrect PIN! " + remaining + " attempts left.");
                } else {
                    System.out.println("❌ Card blocked! Too many failed attempts.");
                }
            }
        }
        
        // Main menu (if authenticated)
        if (isAuthenticated) {
            int choice = 0;
            
            while (choice != 4) {
                System.out.println("\n=== Main Menu ===");
                System.out.println("Account: " + accountName);
                System.out.println("1. Check Balance");
                System.out.println("2. Deposit");
                System.out.println("3. Withdraw");
                System.out.println("4. Exit");
                System.out.print("Enter choice (1-4): ");
                
                choice = scanner.nextInt();
                
                switch (choice) {
                    case 1:
                        // Check balance
                        System.out.println("\n=== Balance Inquiry ===");
                        System.out.println("Current Balance: " + balance + " Kyats");
                        break;
                        
                    case 2:
                        // Deposit
                        System.out.println("\n=== Deposit ===");
                        System.out.print("Enter amount to deposit: ");
                        double depositAmount = scanner.nextDouble();
                        
                        if (depositAmount > 0 && depositAmount <= 1000000) {
                            balance += depositAmount;
                            System.out.println("✓ Deposit successful!");
                            System.out.println("Deposited: " + depositAmount + " Kyats");
                            System.out.println("New Balance: " + balance + " Kyats");
                        } else {
                            System.out.println("❌ Invalid amount! (Max: 1,000,000 Kyats)");
                        }
                        break;
                        
                    case 3:
                        // Withdraw
                        System.out.println("\n=== Withdrawal ===");
                        System.out.print("Enter amount to withdraw: ");
                        double withdrawAmount = scanner.nextDouble();
                        
                        if (withdrawAmount <= 0) {
                            System.out.println("❌ Invalid amount!");
                        } else if (withdrawAmount > balance) {
                            System.out.println("❌ Insufficient balance!");
                            System.out.println("Available: " + balance + " Kyats");
                        } else if (withdrawAmount > 500000) {
                            System.out.println("❌ Daily withdrawal limit: 500,000 Kyats");
                        } else {
                            balance -= withdrawAmount;
                            System.out.println("✓ Withdrawal successful!");
                            System.out.println("Withdrawn: " + withdrawAmount + " Kyats");
                            System.out.println("Remaining Balance: " + balance + " Kyats");
                            
                            // Dispense money simulation
                            System.out.println("\nDispensing money...");
                            int[] notes = {50000, 10000, 5000, 1000};
                            double remaining = withdrawAmount;
                            
                            for (int note : notes) {
                                if (remaining >= note) {
                                    int count = (int)(remaining / note);
                                    System.out.println(note + " Kyats × " + count);
                                    remaining = remaining % note;
                                }
                            }
                        }
                        break;
                        
                    case 4:
                        System.out.println("\n=== Thank You ===");
                        System.out.println("Please take your card.");
                        System.out.println("Have a nice day!");
                        break;
                        
                    default:
                        System.out.println("❌ Invalid choice! Please select 1-4.");
                }
            }
        }
        
        scanner.close();
    }
}

Sample Output:

=== Welcome to A Coder Bank ATM ===
Enter your PIN: 1234
✓ Login successful!

=== Main Menu ===
Account: Aung Aung
1. Check Balance
2. Deposit
3. Withdraw
4. Exit
Enter choice (1-4): 3

=== Withdrawal ===
Enter amount to withdraw: 75000
✓ Withdrawal successful!
Withdrawn: 75000.0 Kyats
Remaining Balance: -25000.0 Kyats

Dispensing money...
50000 Kyats × 1
10000 Kyats × 2
5000 Kyats × 1

=== Main Menu ===
...

🔹 Common While Loop Patterns

Pattern 1: Sentinel-Controlled Loop

Special value (sentinel) ရောက်တဲ့အထိ run:

Java

Scanner scanner = new Scanner(System.in);
int num;

System.out.println("Enter numbers (0 to stop):");

while ((num = scanner.nextInt()) != 0) {
    System.out.println("You entered: " + num);
}

System.out.println("Done!");

Pattern 2: Flag-Controlled Loop

Boolean flag သုံးပြီး control:

Java

boolean keepRunning = true;

while (keepRunning) {
    // Do something
    
    if (someCondition) {
        keepRunning = false;  // Stop the loop
    }
}

Pattern 3: Counter-Controlled (Known Max)

Maximum iterations ရှိတဲ့ validation:

Java

int attempts = 0;
int maxAttempts = 5;
boolean success = false;

while (!success && attempts < maxAttempts) {
    // Try something
    attempts++;
    
    if (successfulOperation) {
        success = true;
    }
}

🎯 အဓိက မှတ်သားရမည့် အချက်များ

While loop: Condition true ဖြစ်သရွေ့ run တယ် (0 or more times)
Do-while loop: အရင် run, နောက် condition စစ် (1 or more times)
Use while when: Iterations မသိ, condition-based, user input validation
Use for when: Iterations သိ, counting, arrays
Always update: Loop variable ကို update လုပ်ဖို့ မမေ့ပါနဲ့ (infinite loop ဖြစ်မယ်)
Break: Loop ကနေ လုံးဝထွက်ဖို့
Continue: Current iteration skip လုပ်ဖို့
Input validation: While loop က perfect (valid input မရသမျှ ထပ်မေး)
Menu systems: Do-while သုံးရင် menu ကို အနည်းဆုံး တစ်ကြိမ် ပြတယ်
Infinite loops: Testing နဲ့ safety counters သုံးပြီး ရှောင်ပါ
Boolean flags: Complex conditions အတွက် boolean variables သုံးပါ

✍️ Practice Exercise

Exercise: Factorial Calculator

While loop သုံးပြီး factorial တွက်တဲ့ program ရေးပါ:

User ကနေ positive number တစ်ခု input ယူပါ
Factorial တွက်ပါ (5! = 5 × 4 × 3 × 2 × 1 = 120)
Input validation လုပ်ပါ (negative numbers reject)
User က "exit" လို့ ရိုက်မှ ရပ်ပါ

Example:

Enter a number (or 'exit' to quit): 5
5! = 120

Enter a number (or 'exit' to quit): 6
6! = 720

Enter a number (or 'exit' to quit): exit
Goodbye!

💡 Solution ကြည့်ရန် (Try လုပ်ပြီးမှ ကြည့်ပါ)

Java

import java.util.Scanner;

public class FactorialCalculator {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String input = "";
        
        System.out.println("=== Factorial Calculator ===");
        
        while (!input.equals("exit")) {
            System.out.print("Enter a number (or 'exit' to quit): ");
            input = scanner.nextLine();
            
            if (input.equals("exit")) {
                System.out.println("Goodbye!");
                break;
            }
            
            try {
                int n = Integer.parseInt(input);
                
                if (n < 0) {
                    System.out.println("Error: Please enter a positive number!");
                    continue;
                }
                
                long factorial = 1;
                int i = 1;
                
                while (i <= n) {
                    factorial *= i;
                    i++;
                }
                
                System.out.println(n + "! = " + factorial);
                
            } catch (NumberFormatException e) {
                System.out.println("Error: Invalid input!");
            }
            
            System.out.println();
        }
        
        scanner.close();
    }
}

📝 Quick Quiz

Question 1: ဒီ while loop က ဘယ်နှစ်ကြိမ် run မလဲ?

int x = 5;
while (x > 3) {
    System.out.println(x);
    x--;
}

1 time 2 times 3 times Infinite

Question 2: Do-while loop နဲ့ while loop ရဲ့ အဓိက ခြားနားချက်က ဘာလဲ?

Do-while က မြန်တယ် Do-while က အနည်းဆုံး တစ်ကြိမ် run တယ် While က condition မစစ်ဘူး ဘာမှ မကွာဘူး

Question 3: ဘယ် scenario မှာ while loop က for loop ထက် ပိုကောင်းလဲ?

Array elements print လုပ်ဖို့ 1 to 100 count လုပ်ဖို့ User က valid password ထည့်သည်အထိ မေးဖို့ Multiplication table ဆွဲဖို့

🎉 Congratulations!

Module 3: Control Flow ပြီးပါပြီ!

သင် သင်ယူပြီးသား အရာများ:

✅ Lesson 9: If-Else Statements
✅ Lesson 10: Switch Statements
✅ Lesson 11: For Loops
✅ Lesson 12: While Loops

Course Progress: 50% Complete!
12 of 24 lessons finished!

Next: Module 4 - Methods 🚀

While Loops: Condition-Based Repetition

🎯 သင် သင်ယူမည့် အရာများ

📖 While Loop ဆိုတာ ဘာလဲ?

For vs While - အဓိက ခြားနားချက်

🔹 Basic While Loop Syntax

Flow Chart

🔹 Simple Example: Count to 10

🔹 Input Validation - While Loop ရဲ့ အင်အား!

Example 1: Password Validation

Example 2: Age Validation

🔹 Menu-Driven Programs

🔹 Do-While Loop

Example: Menu (Must Show At Least Once)

Comparison Example

🔹 Infinite Loops - အန္တရာယ်!

❌ Common Infinite Loop Mistakes

✅ How to Avoid Infinite Loops

Intentional Infinite Loop (With Break)

🔹 Loop Control: Break & Continue

Break Statement

Continue Statement

💻 Complete Example: Number Guessing Game

💻 Advanced Example: ATM Banking System

🔹 Common While Loop Patterns

Pattern 1: Sentinel-Controlled Loop

Pattern 2: Flag-Controlled Loop

Pattern 3: Counter-Controlled (Known Max)

🎯 အဓိက မှတ်သားရမည့် အချက်များ

✍️ Practice Exercise

📝 Quick Quiz

🎉 Congratulations!