y is it a valid declaration in java: int f=1_0;

Question

I found a question in challenge which asked me to select all valid declarations in Java. I didn't select 'int f=1_0;' n hence I got the answer wrong. When I checked the answer, int f=1_0; was also chosen n my oppent had also chosen it.

Answer 1

thankya

Answer 2

The _ is a digit separator in Java, just as , is in natural language outside Europe at least, where they use . instead of ,. It was introduced in Java 7 if I recall correctly. so, in the question, f=10.