🧮 Java Console Calculator

The Java Console Calculator is a simple command-line application built using core Java concepts such as loops, conditionals, switch statements, and the Scanner class for user input. It allows users to perform basic arithmetic operations including Addition, Subtraction, Multiplication, and Division interactively through the console.

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⚙️ Features

• ➕ Addition
• ➖ Subtraction
• ✖️ Multiplication
• ➗ Division
• 🧩 Handles invalid inputs gracefully
• 🔁 Continuous execution using loops
• 🚪 Exit functionality to stop the calculator safely

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💻 Technologies Used

• Java (Core Java)
• Scanner Class for user input
• Switch-Case Statements for operation selection
• Loops for repeated calculations

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🧠 Concepts Demonstrated

• Input/Output handling using java.util.Scanner
• Control flow using conditional and iterative statements
• Basic arithmetic logic in Java
• Program structure with modular code
• (Optional) Handling divide-by-zero using exception handling

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🚀 How to Run

1. Clone the repository:

   git clone https://github.com/sarwdeep/Java-Console-Calculator.git
   
   
   

Java Basic Questions and Answers

1. What is method overloading?
   Method overloading occurs when multiple methods in the same class share the same name but differ in the number or type of parameters. The compiler determines which method to invoke based on the argument list.

2. How do you handle divide-by-zero?
   Divide-by-zero can be handled using conditional checks (if-else) to prevent division when the denominator is zero, or by using exception handling (try-catch) to catch ArithmeticException.

3. Difference between == and .equals()?
   == compares object references (i.e., whether two variables refer to the same memory location), whereas .equals() compares the contents or values of the objects.

4. What are the basic data types in Java?
   Java has eight primitive data types: byte, short, int, long, float, double, char, and boolean.

5. How is Scanner used for input?
   The Scanner class (from java.util package) is used to take user input from the console. It can read different data types such as integers, strings, and doubles using methods like nextInt(), nextLine(), and nextDouble().

6. Explain the role of a loop.
   Loops are used to execute a block of code repeatedly, reducing redundancy. They continue running until a specified condition becomes false.

7. Difference between while and for loop?
   A for loop is typically used when the number of iterations is known in advance (uses initialization, condition, and update in one line).
   A while loop is used when the number of iterations is not known beforehand and depends on a condition being true.

8. What is the JVM?
   The Java Virtual Machine (JVM) is an engine that runs Java bytecode. It provides a runtime environment that converts bytecode into machine code, allowing Java programs to run on any device or operating system.

9. How is Java platform-independent?
   Java is platform-independent because its compiler converts source code into bytecode, which is executed by the JVM. The JVM is system-specific, so the same bytecode can run on any platform with a JVM.

10. How do you debug a Java program?
    A Java program can be debugged using IDE tools (like breakpoints in IntelliJ or Eclipse) or by printing variable values to the console. You can also use the command line debugger (jdb) to trace execution and find logical errors.