🔄 Control Flow Statements

Master decision-making and repetition in Java with visual flowcharts and real-world applications

🎯 Learning Objectives

By the end of this lesson, you will:

• Master conditional statements with complex decision trees
• Understand all loop constructs and their optimal use cases
• Visualize program flow with flowcharts and execution patterns
• Apply control flow in real-world programming scenarios

🧠 Control Flow Architecture

<aside> 🎭

Program Flow Philosophy

Control flow is the heartbeat of programming - it determines how your program makes decisions, repeats actions, and responds to different conditions. Think of it as the GPS of your code!

</aside>

The Decision-Making Hierarchy

Program Execution Flow
═══════════════════════════════════════════════════════════════

Sequential Flow:      Decision Flow:        Repetitive Flow:
   ┌─────────┐          ┌─────────┐           ┌─────────┐
   │ Step 1  │          │Condition│           │  Loop   │
   └────┬────┘          └────┬────┘           └────┬────┘
        │                   ╱│╲                    │ ↑
   ┌────▼────┐          ╱   │  ╲                   │ │
   │ Step 2  │       Yes╱    │   ╲No               │ │
   └────┬────┘        ╱      │    ╲                │ │
        │       ┌────▼──┐    │   ┌─▼───┐           │ │
   ┌────▼────┐  │Action1│    │   │Action│           └─┘
   │ Step 3  │  └───────┘    │   │  2  │        Repeat
   └─────────┘               │   └─────┘       Until Done

🚦 Conditional Statements Mastery

if-else Decision Tree

<aside> 🌳

Decision Tree Visualization

Think of if-else as a flowchart where each condition is a branch point leading to different actions.

</aside>

// 🎯 Practical Example: Student Grade Calculator
public class GradeCalculator {
    
    public static String calculateGrade(int score, boolean hasExtraCredit) {
        String grade;
        String performance;
        
        // Multi-level decision making
        if (score >= 97 || (score >= 95 && hasExtraCredit)) {
            grade = "A+";
            performance = "Outstanding! 🌟";
        } else if (score >= 93) {
            grade = "A";
            performance = "Excellent work! 🎯";
        } else if (score >= 90) {
            grade = "A-";
            performance = "Great job! 👍";
        } else if (score >= 87) {
            grade = "B+";
            performance = "Good work! 📈";
        } else if (score >= 83) {
            grade = "B";
            performance = "Solid effort! 💪";
        } else if (score >= 80) {
            grade = "B-";
            performance = "Keep improving! 📚";
        } else if (score >= 77) {
            grade = "C+";
            performance = "Need more practice! 🔄";
        } else if (score >= 73) {
            grade = "C";
            performance = "Study harder! 📖";
        } else if (score >= 70) {
            grade = "C-";
            performance = "Focus on basics! 🎯";
        } else if (score >= 60) {
            grade = "D";
            performance = "Needs significant improvement! ⚠️";
        } else {
            grade = "F";
            performance = "Must retake course! 🔄";
        }
        
        return String.format("Grade: %s - %s (Score: %d)", grade, performance, score);
    }
}

Visual Decision Flow Chart