This still uses preview features though. However, like you demonstrated already, compilation is no longer a required step for simplistic programs like this.
It must be somewhere under the hood. Otherwise, it wont be callable and it would require an instance of an object to call. Unless the object here is the Java environment?
No String[] args
They are just optional I’m sure, like C and C++. You still need them to read command line arguments.
All in all, these syntax improvements are welcome. I already moved on to Kotlin for Android development though.
It must be somewhere under the hood. Otherwise, it wont be callable and it would require an instance of an object to call. Unless the object here is the Java environment?
If an unnamed class has an instance main method rather than a static main method then launching it is equivalent to the following, which employs the existing anonymous class declaration construct:
new Object() {
// the unnamed class's body
}.main();
No String[] args
They are just optional I’m sure, like C and C++. You still need them to read command line arguments.
Without the preview feature enabled, it is not an optional part of the method signature. It specifically looks for a main(String[]) signature.
I am not in the mood to read a technical document, but I don’t think the resulting binary/byte code should be different between the two “hello world” programs. But then again, why not?
Without the preview feature enabled, it is not an optional part of the method signature. It specifically looks for a main(String[]) signature.
Ah ha! So that’s what’s going on here. They almost got it right. They had the potential to make a lot of the boilerplate optional or implicit under relevant circumstances, but instead the language has two explicit switchable modes.
Can I write a Java application in “preview feature”?
This is getting a little better nowadays.
> cat Hello.java void main() { System.out.println("Hello, World!"); } > java --enable-preview Hello.java Hello, World!Things to notice:
public staticString[] args.This still uses preview features though. However, like you demonstrated already, compilation is no longer a required step for simplistic programs like this.
It must be somewhere under the hood. Otherwise, it wont be callable and it would require an instance of an object to call. Unless the object here is the Java environment?
They are just optional I’m sure, like C and C++. You still need them to read command line arguments.
All in all, these syntax improvements are welcome. I already moved on to Kotlin for Android development though.
No. From JEP-445:
Without the preview feature enabled, it is not an optional part of the method signature. It specifically looks for a
main(String[])signature.I am not in the mood to read a technical document, but I don’t think the resulting binary/byte code should be different between the two “hello world” programs. But then again, why not?
Ah ha! So that’s what’s going on here. They almost got it right. They had the potential to make a lot of the boilerplate optional or implicit under relevant circumstances, but instead the language has two explicit switchable modes.
Can I write a Java application in “preview feature”?
Microsoft Java is a one-liner these days.
> cat program.cs Console.WriteLine("Hello, World!"); > dotnet run Hello, World!