My Java Learning Blog - Introduction to classes, variables and methods

Introduction

In today’s session, we continued our journey with Java programming and started working with Eclipse IDE to organize and write our code. This was my first experience in creating a proper project structure in Eclipse, and it helped me understand how Java programs are built step by step.

What We Learned

1. Classes:
   A class in Java acts as a blueprint for creating objects. It defines the structure of a program by containing both variables and methods. Every Java program begins with at least one class.

2. Variables and Their Types:
   Variables are named storage containers used to hold data. We learned about several types:

int – for whole numbers
double – for decimal numbers
char – for single characters
boolean – for values that are either true or false
String – for text

There are also two important categories of variables in Java:

Instance Variable: Declared inside a class but outside any method. Its value is unique for each object.

Local Variable: Declared inside a method and can only be used within that method.

Example:

public class Student {
    // Instance variable
    String name = "John"; 

    public void studentdetails() {
        // Local variable
        int age = 18;  
    }
 }

Methods and Their Types:
Method is a block of code which executes a specific task.
Types of methods:

• Methods with return type: Return a specific value.
• Methods without return type: Declared with void keyword and return nothing.
• Methods with arguments: Accept inputs.
• Methods without arguments: Do not take any inputs.

Practical Work in Eclipse

During the practical session, we created a new project in Eclipse. Inside the src folder, we added a new package to organize our work. Then, within the package, we created a new class that contained the method. This allowed us to test simple programs and get familiar with Eclipse’s project structure.

Thoughts

This session gave me a clear understanding of how classes, variables, and methods come together to form the foundation of Java programming. I am looking forward to exploring more features of Java and building more complex programs in the future.