Basic Java Program for Operators, Variables, and Control Flow Statements

 

1. Variables and Operators in Java

A variable is used to store data, and operators perform operations on these variables.

Example: Arithmetic Operators

public class BasicOperators {
    public static void main(String[] args) {
        int a = 10, b = 5;

        System.out.println("Sum: " + (a + b)); 
        System.out.println("Difference: " + (a - b)); 
        System.out.println("Product: " + (a * b)); 
        System.out.println("Quotient: " + (a / b)); 
        System.out.println("Remainder: " + (a % b)); 
    }
}

Explanation:

• + (Addition), - (Subtraction), * (Multiplication), / (Division), % (Modulo) are used to perform arithmetic calculations.

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2. Control Flow Statements in Java

Control flow statements decide the execution path of the program based on conditions.

Example: If-Else Statement

public class IfElseExample {
    public static void main(String[] args) {
        int num = 10;

        if (num > 0) {
            System.out.println("The number is positive.");
        } else {
            System.out.println("The number is not positive.");
        }
    }
}

Explanation:

• if checks a condition; if true, it executes the block inside { }.
• If false, it moves to else block.

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Example: Switch Case

public class SwitchExample {
    public static void main(String[] args) {
        int day = 2;

        switch (day) {
            case 1:
                System.out.println("Monday");
                break;
            case 2:
                System.out.println("Tuesday");
                break;
            case 3:
                System.out.println("Wednesday");
                break;
            default:
                System.out.println("Other day");
        }
    }
}

Explanation:

• The switch statement is used when we have multiple possible values for a variable.
• break ensures the program exits after finding the correct case.

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Example: Loops (for, while, do-while)

For Loop:

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

Explanation:

• for loop repeats execution from i = 1 to i = 5.

While Loop:

public class WhileLoopExample {
    public static void main(String[] args) {
        int i = 1;
        while (i <= 5) {
            System.out.println("Count: " + i);
            i++;
        }
    }
}

Explanation:

• while loop runs until the condition (i <= 5) becomes false.

Do-While Loop:

public class DoWhileExample {
    public static void main(String[] args) {
        int i = 1;
        do {
            System.out.println("Count: " + i);
            i++;
        } while (i <= 5);
    }
}

Explanation:

• The do-while loop ensures the code runs at least once, even if the condition is false.

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Summary:

✅ Variables store values.
✅ Operators perform calculations.
✅ If-else decides execution based on a condition.
✅ Switch handles multiple choices.
✅ Loops repeat tasks multiple times.

These basics are the foundation of Java programming! 🚀