Getting error on commented line

Question

  class k{
  public static void main(String[] args) {
   //('\u000d'); 
   }
}

In class k after main i have commented out line number 3 but still getting error unclosed character literal ,what could be the reason for it?

See http://stackoverflow.com/questions/3866187/why-i-cant-use-u000d-and-u000a-as-cr-and-lf-in-java — Code-Apprentice, Jul 05 '14 at 18:05

Elliott Frisch · Accepted Answer · 2014-07-05T18:09:07.397

12

Unicode characters are parsed very early in the Java compilation, anyway \u000d isn't a valid character.

// The other style comments work.
/*('\u000d'); */

Edit

\u000d is converted into a newline, which ends your comment...

//('\u000d');

gets converted into

    //('
') // <-- bare line with ')

which isn't a valid character constant.

edited Jul 05 '14 at 18:09

answered Jul 05 '14 at 17:53

Elliott Frisch

Can you explain what you mean by "\u000d isn't a valid character"? – Code-Apprentice Jul 05 '14 at 18:04
@Code-Apprentice Edited to add more explanation – Elliott Frisch Jul 05 '14 at 18:09

score 4 · Answer 2 · answered Jul 05 '14 at 18:02

4

It appears that '\u000d' is a newline character. The compiler sees the single line of code as two lines:

//('
');

This is why you get the error. The second line has an opening single-quote, but no closing one to match.

answered Jul 05 '14 at 18:02

Code-Apprentice

score 3 · Answer 3 · answered Jul 05 '14 at 18:03

3

It's a character literal. \u000d means "newline". While being in a commented line may seem to you like nothing in it is handled, this happens:

original : {
  //('\u000d');
}

pre-compile : {
  //('
'); // <- This is syntax error!!!
}

answered Jul 05 '14 at 18:03

Unihedron

3 Answers3