Java 10 (JDK 10) was released on March 20, 2018, so let's try Hello World.

Install Java SE Development Kit 10 on macOS Sierra

From Java SE Development Kit 10 --Downloads, the installer for the JDK for macOS jdk-10_osx-x64_bin Download .dmg.

Open jdk-10_osx-x64_bin.dmg. Double click to install.

Requires 700MB or more free space.

Confirm that the installation was successful.

$ java -version
java version "10" 2018-03-20
Java(TM) SE Runtime Environment 18.3 (build 10+46)
Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10+46, mixed mode)

$ javac -version
javac 10

Try Hello World

Sample code HelloWorld.java is prepared to use the type inference (JEP 286: Local \ -Variable Type Inference) that seems to have been introduced in Java 10. Declare the variable message, which is known to contain the String type, with var.

public class HelloWorld {

  public static void main(String[] args) {
    var message = args[0];
    System.out.println(message);
  }
}

compile.

$ javac HelloWorld.java 

Run. It worked as expected.

$ java HelloWorld "hello, world"
hello, world

Reference material

• JDK 10 Documentation
• Java SE Development Kit 10- - Downloads -Java 10 is officially released today. Type inference of local variables, replaceable garbage collector, non-volatile memory support, etc. Java 9 is already out of support-Publickey -Java 10 new feature summary -Qiita
• JEP 286: Local-Variable Type Inference