A unicode newline character(\\u000d) in Java

问题:

Let's see the following code snippet in Java.

public class Main {
    public static void main(String[] args) {
        // new Character(' \u000d System.out.println("Hello");
    }
}

---

In the above code, although the only line in the main() method is commented out, it displays the output Hello on the console, even though it looks like that this commented line contains some syntax errors. If this line is uncommented, it will not work at all, causing a compile-time error.

Why does it output "Hello" here?

回答1:

Java parses character escape codes in source code, not just strings.
This allows you to use Unicode identifiers without a Unicode encoding.

Therefore, the \u000d in the comment is parsed as a newline, ending the comment and beginning an instance initializer.