Learn JShell with Java 9 - Step by Step
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- 1 article
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- Certificate of Completion
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Try Udemy for Business- You will be able to write Java Programs and Snippets using Java REPL JShell
- You will understand all the important tips and tricks about the Java REPL JShell
- You will understand and use important Java REPL JShell Commands
- You will become a more productive Java developer with JShell
- You will learn to create Java variables, methods and classes with JShell
- You will learn to explore external Java Libraries with JShell
- You will learn JShell tips to become a more effective Java Programmer
- Java REPL (Read Evaluate Print Loop) Shell
- Comes by default with JDK 9
- Quickly debug or test or investigate an API or try a new Library
- Quick Learning with immediate feedback. No need to write a PSVM or a Unit test.
- Install JDK 9
- Open Command Prompt and type in jshell
- Other option is to cd to the bin folder where JDK 9 is installed and type in jshell
- /exit
- int i=10;
- int i=10; int j=10; //multiple statements
- System.out.println(i);
- i = i + j
```
1 : int x = 10;
2 : x
4 : x = x + 10;
5 : System.out.println(x);
6 : int i = 10;
7 : int j = 20;
8 : i = i + 10;
9 : j = j + 10;
```
- Tip : Semicolon is not mandatory unless you want to seperate statements on a single line.
- Tip : Comments are supported //
- Quick Tip - Nothing is saved by default!
- Quick Tip - Verbose mode!
- jshell -v
- Default imports
- /imports
- importing a new Java class
- 2 options - import statement or auto import
- import java.sql.Timestamp
- new Timestamp => Shift + Tab i
- Creating a new Java variable using imported class
- new Timestamp(); => Shift + Tab v
- new Timestamp(1000L);=> Shift + Tab v
- Timestamp temp = new Timestamp(1000L);
- You should be an experienced Java Programmer
- You should have Java 9 installed on your computer
JShell is a new feature in Java 9 which allows you to run code quickly and easily. In this course, you will learn how to use Java REPL JShell to become a more productive programmer. You will learn how to explore Java with JShell and understand the various JShell commands. Added in are tips and tricks to make you a JShell expert.
Here are the step by step details:
- Introduction to JShell
- Installing and Launching JShell
- JShell Basics - Java Variables and Expressions
- JShell Basics - Few important tips
- JShell Commands - list, drop and history
- JShell Basics - Multiple Lines
- JShell Tip - Implicit or Scratch Variables and Feedback options
- JShell Basics - Java Methods
- JShell Basics - Java Imports
- JShell Tip - Forward Referencing
- JShell Basics - Java Class
- JShell Basics - Java Auto completion
- More JShell Tips : Exceptions, var, methods and types Commands and Help
- Saving and Reloading JShell Sessions
- JShell - Setting Custom Start Options
- JShell - Playing around with an External Library
- More JShell Tips
- You are a good Java Programmer and want to learn the most important new feature in Java 9 - JShell
- You want to become more productive at exploring Java APIs and Libraries