Java Operators - Complete Guide

public class ArithmeticOperators {
    public static void main(String[] args) {
        int a = 20, b = 7;
        
        // Basic arithmetic operations
        System.out.println("a = " + a + ", b = " + b);
        System.out.println("a + b = " + (a + b));   // Addition: 27
        System.out.println("a - b = " + (a - b));   // Subtraction: 13
        System.out.println("a * b = " + (a * b));   // Multiplication: 140
        System.out.println("a / b = " + (a / b));   // Division: 2 (integer division)
        System.out.println("a % b = " + (a % b));   // Modulus: 6
        
        // Floating point division
        double x = 20.0, y = 7.0;
        System.out.println("\nFloating point division:");
        System.out.println("x / y = " + (x / y));   // 2.857142857142857
        
        // Increment and decrement operators
        int counter = 5;
        System.out.println("\nIncrement/Decrement:");
        System.out.println("Original counter: " + counter);
        System.out.println("Post-increment (counter++): " + (counter++)); // 5
        System.out.println("After post-increment: " + counter);           // 6
        System.out.println("Pre-increment (++counter): " + (++counter));  // 7
        System.out.println("After pre-increment: " + counter);            // 7
        
        // Compound assignment operators
        int total = 10;
        total += 5;  // total = total + 5
        System.out.println("\nAfter total += 5: " + total);  // 15
        
        total *= 2;  // total = total * 2
        System.out.println("After total *= 2: " + total);    // 30
        
        total %= 7;  // total = total % 7
        System.out.println("After total %= 7: " + total);    // 2
    }
}

public class LogicalOperators {
    public static void main(String[] args) {
        int age = 25;
        boolean hasLicense = true;
        int score = 85;
        
        // Relational operators
        System.out.println("Age comparisons:");
        System.out.println("age > 18: " + (age > 18));      // true
        System.out.println("age < 21: " + (age < 21));      // false
        System.out.println("age >= 25: " + (age >= 25));    // true
        System.out.println("age <= 30: " + (age <= 30));    // true
        System.out.println("age == 25: " + (age == 25));    // true
        System.out.println("age != 30: " + (age != 30));    // true
        
        // Logical operators
        System.out.println("\nLogical operations:");
        System.out.println("Can drive? " + (age >= 18 && hasLicense));  // true
        System.out.println("Is teenager or senior? " + 
                          ((age >= 13 && age <= 19) || age >= 65));     // false
        
        boolean isPassing = score >= 60;
        boolean isExcellent = score >= 90;
        System.out.println("\nScore analysis:");
        System.out.println("Score: " + score);
        System.out.println("Is passing: " + isPassing);                // true
        System.out.println("Is excellent: " + isExcellent);            // false
        System.out.println("Is good but not excellent: " + 
                          (isPassing && !isExcellent));                // true
        
        // Short-circuit evaluation
        System.out.println("\nShort-circuit evaluation:");
        boolean result = (score > 100) && (someMethod());  // someMethod() not called
        System.out.println("Result: " + result);
        
        // Ternary operator
        String grade = score >= 90 ? "A" : 
                      score >= 80 ? "B" : 
                      score >= 70 ? "C" : 
                      score >= 60 ? "D" : "F";
        System.out.println("\nGrade: " + grade);  // B
    }
    
    static boolean someMethod() {
        System.out.println("This method was called");
        return true;
    }
}

public class BitwiseOperators {
    public static void main(String[] args) {
        int a = 5;    // Binary: 0101
        int b = 3;    // Binary: 0011
        
        System.out.println("a = " + a + " (Binary: " + Integer.toBinaryString(a) + ")");
        System.out.println("b = " + b + " (Binary: " + Integer.toBinaryString(b) + ")");
        
        // Bitwise AND
        int andResult = a & b;  // 0101 & 0011 = 0001 (1 in decimal)
        System.out.println("\na & b = " + andResult + 
                          " (Binary: " + Integer.toBinaryString(andResult) + ")");
        
        // Bitwise OR
        int orResult = a | b;   // 0101 | 0011 = 0111 (7 in decimal)
        System.out.println("a | b = " + orResult + 
                          " (Binary: " + Integer.toBinaryString(orResult) + ")");
        
        // Bitwise XOR
        int xorResult = a ^ b;  // 0101 ^ 0011 = 0110 (6 in decimal)
        System.out.println("a ^ b = " + xorResult + 
                          " (Binary: " + Integer.toBinaryString(xorResult) + ")");
        
        // Bitwise NOT (complement)
        int notResult = ~a;     // ~0101 = 11111111111111111111111111111010
        System.out.println("~a = " + notResult + 
                          " (Binary: " + Integer.toBinaryString(notResult) + ")");
        
        // Left shift (multiply by 2^n)
        int leftShift = a << 1; // 0101 << 1 = 1010 (10 in decimal)
        System.out.println("\na << 1 = " + leftShift + 
                          " (Binary: " + Integer.toBinaryString(leftShift) + ")");
        
        // Right shift (divide by 2^n, preserves sign)
        int rightShift = a >> 1; // 0101 >> 1 = 0010 (2 in decimal)
        System.out.println("a >> 1 = " + rightShift + 
                          " (Binary: " + Integer.toBinaryString(rightShift) + ")");
        
        // Unsigned right shift (pads with 0)
        int negative = -8;      // Binary: 11111111111111111111111111111000
        int unsignedShift = negative >>> 1;
        System.out.println("\n-8 >>> 1 = " + unsignedShift + 
                          " (Binary: " + Integer.toBinaryString(unsignedShift) + ")");
        
        // Practical example: Checking if number is even/odd
        int number = 42;
        boolean isEven = (number & 1) == 0;  // Last bit 0 = even, 1 = odd
        System.out.println("\n" + number + " is even: " + isEven);
    }
}