Introduction

In Java, tokens are the smallest elements of a program, such as keywords, identifiers, literals, operators, and separators. Expressions are combinations of variables, operators, and method calls that evaluate to a value. Control structures like if-else, switch, loops, and conditional operators help control the flow of execution in a program. This lab introduces Java programming concepts like decision-making, looping, arithmetic, relational, logical, and bitwise operations.

Objectives

The objectives of this lab are:

To understand Java tokens, expressions, and operators
To use control structures like if-else, switch, loops, and conditional operators
To perform arithmetic, relational, logical, and bitwise operations
To implement practical examples using Java programming constructs

Program 1: Find the Smallest Number Using `if-else`

Source Code:

SmallestNumber.java

import java.util.Scanner;

public class SmallestNumber {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter first number: ");
        int a = sc.nextInt();
        System.out.print("Enter second number: ");
        int b = sc.nextInt();
        System.out.print("Enter third number: ");
        int c = sc.nextInt();

        int smallest;
        if (a < b && a < c) {
            smallest = a;
        } else if (b < c) {
            smallest = b;
        } else {
            smallest = c;
        }

        System.out.println("Smallest number is: " + smallest);
        sc.close();
    }
}

Output:

Program 2: Find the Grade Using `switch-case`

Source Code:

StudentGrade.java

import java.util.Scanner;

public class StudentGrade {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter marks (0-100): ");
        int marks = sc.nextInt();

        int grade = marks / 10;
        switch (grade) {
            case 10:
            case 9:
                System.out.println("Grade: A+");
                break;
            case 8:
                System.out.println("Grade: A");
                break;
            case 7:
                System.out.println("Grade: B+");
                break;
            case 6:
                System.out.println("Grade: B");
                break;

            case 5:
                System.out.println("Grade: C+");
                break;
            case 4:
                System.out.println("Grade: C");
                break;
            default:
                System.out.println("Grade: F");
        }
        sc.close();
    }
}

Output:

Program 3: Fibonacci Series

Source Code:

FibonacciSeries.java

import java.util.Scanner;

public class FibonacciSeries {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter number of terms: ");
        int n = sc.nextInt();

        int a = 0, b = 1;
        System.out.print("Fibonacci series: ");
        for (int i = 1; i <= n; i++) {
            System.out.print(a + " ");
            int next = a + b;
            a = b;
            b = next;
        }
        sc.close();
    }
}

Output:

Program 4: Demonstrate `break` and `continue`

`BreakAndContinueDemo.java`

public class BreakAndContinueDemo {
    public static void main(String[] args) {
        System.out.println("Demonstrate break:");
        for (int i = 1; i <= 5; i++) {
            if (i == 3) break;
            System.out.println(i);
        }

        System.out.println("Demonstrate continue:");
        for (int i = 1; i <= 5; i++) {
            if (i == 3) continue;
            System.out.println(i);
        }
    }
}

Output:

Program 5: Arithmetic Operations

`ArithmeticOperations.java`

import java.util.Scanner;

public class ArithmeticOperations {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter first number: ");
        int a = sc.nextInt();
        System.out.print("Enter second number: ");
        int b = sc.nextInt();

        System.out.println("Addition: " + (a + b));
        System.out.println("Subtraction: " + (a - b));
        System.out.println("Multiplication: " + (a * b));
        System.out.println("Division: " + (a / b));
        System.out.println("Modulus: " + (a % b));

        sc.close();
    }
}

Output:

Program 6: Compare Two Integers Using Relational Operators

`RelationalOperatorsDemo.java`

import java.util.Scanner;

public class RelationalOperatorsDemo {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter first integer: ");
        int a = sc.nextInt();
        System.out.print("Enter second integer: ");
        int b = sc.nextInt();

        System.out.println("a == b: " + (a == b));
        System.out.println("a != b: " + (a != b));
        System.out.println("a > b: " + (a > b));
        System.out.println("a < b: " + (a < b));
        System.out.println("a >= b: " + (a >= b));
        System.out.println("a <= b: " + (a <= b));

        sc.close();
    }
}

Output:

Program 7: Demonstrate Logical Operators

`LogicalOperatorsDemo.java`

public class LogicalOperatorsDemo {
    public static void main(String[] args) {
        boolean a = true;
        boolean b = false;

        System.out.println("a && b: " + (a && b));
        System.out.println("a || b: " + (a || b));
        System.out.println("!a: " + (!a));
        System.out.println("!b: " + (!b));
    }
}

Output:

Program 8: Bitwise Operations

`BitwiseOperations.java`

import java.util.Scanner;

public class BitwiseOperations {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter first integer: ");
        int a = sc.nextInt();
        System.out.print("Enter second integer: ");
        int b = sc.nextInt();

        System.out.println("a & b = " + (a & b));
        System.out.println("a | b = " + (a | b));
        System.out.println("a ^ b = " + (a ^ b));
        System.out.println("~a = " + (~a));
        System.out.println("a << 1 = " + (a << 1));
        System.out.println("a >> 1 = " + (a >> 1));

        sc.close();
    }
}

Output:

Program 9: Smallest of Three Numbers Using Conditional Operator

`SmallestConditional.java`

import java.util.Scanner;

public class SmallestConditional {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter first number: ");
        int a = sc.nextInt();
        System.out.print("Enter second number: ");
        int b = sc.nextInt();
        System.out.print("Enter third number: ");
        int c = sc.nextInt();

        int smallest = (a < b) ? (a < c ? a : c) : (b < c ? b : c);
        System.out.println("Smallest number is: " + smallest);

        sc.close();
    }
}

Output:

Program 10: Swap Two Numbers Without Using a Third Variable

`SwapNumbers.java`

import java.util.Scanner;

public class SwapNumbers {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter first number: ");
        int a = sc.nextInt();
        System.out.print("Enter second number: ");
        int b = sc.nextInt();

        System.out.println("Before swap: a = " + a + ", b = " + b);

        a = a + b;
        b = a - b;
        a = a - b;

        System.out.println("After swap: a = " + a + ", b = " + b);
        sc.close();
    }
}

Output:

Conclusion

In this lab, we explored tokens, expressions, and control structures in Java. We learned how to:

Use if-else and switch-case statements for decision-making
Implement loops and control statements like break and continue
Perform arithmetic, relational, logical, and bitwise operations
Use the conditional operator and swap variables efficiently
This lab strengthens the foundation for writing more complex programs using Java’s control structures.