What's up with Java's "%n" in printf?

From a quick google:

There is also one specifier that doesn't correspond to an argument. It is "%n" which outputs a line break. A "\n" can also be used in some cases, but since "%n" always outputs the correct platform-specific line separator, it is portable across platforms whereas"\n" is not.

Please refer https://docs.oracle.com/javase/tutorial/java/data/numberformat.html

Original source

%n is portable across platforms \n is not.

See the formatting string syntax in the reference documentation:

'n' line separator The result is the platform-specific line separator

While \n is the correct newline character for Unix-based systems, other systems may use different characters to represent the end of a line. In particular, Windows system use \r\n, and early MacOS systems used \r.

By using %n in your format string, you tell Java to use the value returned by System.getProperty("line.separator"), which is the line separator for the current system.