How many days required to learn Java

Java programming is one of the mostly used programming languages. In the IT world, there are more than 8 million Java developers. The count of Java developers is rapidly growing. Learning Java doesn't make it possible to happen overnight, and it takes time and practice. It is very difficult to give the correct answer to the question of how many days required to learn Java? Because each person has not the same strength or learning power.

The scope of Java programming is immense and provides a lot of carrier opportunities in the IT field. Everyone wants to learn Java programming as soon as possible, but it is not easy. To become a successful Java developer, the only way is to do the practice of all basics and advanced concepts of it.

If we follow the following learning path, we can learn Java in one month only.

1) Day 1-2: Learn Fundamentals

If we are beginners in Java programming or other programming languages, we need to clear all the basics fundamentals of that language. Before diving into the core concept of Java, we need to learn about the introduction of language, features, applications, etc. After that, we should know how we can set up the Java runtime environment. We should also have to learn how we can create, compile and run the "Hello World" java program. At this level, we also need to explore the IDEs that help us to do Java programming. So, in the end of the day, we have knowledge of the following concepts:

1. Introduction of Java
2. Features of Java
3. JVM(Java Virtual Machine)
4. Java Environment
5. Hello World program
6. Java IDEs

2) Day 3-5: Learn Variables, DataTypes and Conditional Statements

After getting all the basics of Java programming, we are ready to go to the next step. We need to know some important concepts of Java-like DataTypes, Variables, and Conditional Statements. These concepts are the prerequisites for all the programming languages. In these two days we should have to gain knowledge of:

1. Different types of data types in Java.
2. How variables are created or initialize in Java.
3. What are the conditional statements, and how we can implement these conditional statements?
4. What are the operators and modifiers, and how they are implemented in Java?
5. All the looping statements like for loop.

In the end of the day, we should create basic programs like swapping of numbers, Fibonacci series, Factorial, etc.

3) Day 6-8: Learn Arrays, ArrayList, and string manipulation concepts

After getting the knowledge of Java programming's prerequisites, we are ready to move on to some advanced concepts of it. In Java, String and Array are both important, and the developer should have detailed knowledge of them. At this step, we have to gain knowledge about:

1. Strings.
2. What is an array, and how we create it in Java? We also have to get knowledge about how we can access the elements from it.
3. Scope of variables.
4. How can we perform the type conversion in Java?
5. How are switch statements used in Java?

Note: Moving to the next step, you have to make sure that all the above-discussed concepts are cleared in your mind.

4) Day 9-12: Learn Objects, Classes and Methods

After getting knowledge about all the mentioned topics, we will have a decent base, which is necessary to learn any programming language. Now, we know that Java follows the concepts of OOPs, so we have to clear the concepts of Java's basic building blocks. We have to get the answers to all the following questions.

1. What are Objects and Classes, and how we can create them in Java?
2. What are the methods in Java, and how we create them?
3. What is Overloading and Overriding in Java?
4. How can we pass the parameters in Java?
5. What are the constructors, and what is the role of it in Java?

5) Day 13-16: Learn Advance OOPs concepts

Now, we are ready to dive into core Java programming. At this stage, we should have proper knowledge of Objects, Classes, and Methods. To learn Java, we should have command on the Oops concepts like Polymorphism, Encapsulation, Inheritance, and Abstraction because Java works on these principles. We should have to gain knowledge of the following concepts in two days.

1. Inheritance
2. Polymorphism or Runtime Polymorphism and Compile-time Polymorphism.
3. Abstraction
4. Encapsulation
5. Different keywords like This and Super.
6. Composition
7. Aggregation
8. Association

6) Day 17-20: Interfaces and Packages

After knowing all the principles mentioned above, we are ready to go one step more. We have to learn about the Packages, Interfaces, Nested interfaces, and Abstract Classes in these four days. There are several packages like "Java.Lang", "Java.Time", and "Java.Math" are mostly used in Java programming.

An interface can have several abstract methods, and if we implement that interface, we need to define its abstract methods in our programs. For that, we should have proper knowledge of interfaces and abstract classes and methods.

So, in the end of the day, we should have knowledge of the following concepts:

1. Package
2. Interface
3. Abstract Class and Method
4. Nested Interface
5. Time, Lang, Math and other packages.

7) Day 21-25: Exception Handling, Thread, Multithreading and I/O Streams concepts

Our program is always executed without having any error is not possible. There is always a chance of getting an error when we execute our program. So, we need to handle these errors so that our programs can execute even if it gets an error. We also have knowledge of how we can work with Files and use Regular Expressions in Java. Apart from that, we also have to gain knowledge of Thread and Multithreading concepts in Java.

So, in the end of the day, we should have knowledge of the following concepts:

1. Exception Handling
2. Types of Exception
3. Thread Concept
4. Multithreading
5. Regular Expression
6. File Handling

8) Day 26-30: Collection Framework, AWT and Swings

Before going to the next step, we have to emphasize the implementation aspects of all the concepts and theoretical knowledge mentioned above. After that, we are ready to get knowledge about the advanced concepts. Collection Framework, Abstract Window Toolkit, and Swings are the most important advanced concept of Java. The Collection Framework defines several classes and interfaces to represent a collection of the object as a single unit. So, in the end of the day, we should have knowledge of the following concepts:

1. Collections in Java
2. Java Swings
3. Generics
4. AWT

After one month, we have to do practice and only practice. We can also put our hands-on small projects and understand how the concepts work concurrently to complete a process.