Why does Java execute code hidden in comments via Unicode?

Hi everyone! I recently started learning Java and came across strange behavior. I'm writing simple code: ```java public class Test { public static void main(String[] args) { // \u000d System.out.println("Hello from comment!"); System.out.println("Hello world"); } } ``` I expected this code to output only "Hello world" because the second line is a comment. But when I run it, I get: ``` Hello from comment! Hello world ``` How is this possible? I thought comments are completely ignored by the compiler. Why does code inside a comment get executed? Is this a compiler bug or is it intentional? I googled it but couldn't find a clear explanation for a beginner. Please explain how this Unicode magic works. And is there any way to protect against such "surprises" in code?