Java output - A strange equality

Question

Why is 234 == 23_4?

public class Program
{
public static void main(String[] args) {
int x = 234;
boolean y = (x==23_4);
System.out.println(y);
}
}

Answer 1

Underscores in Numeric Literals
https://www.sololearn.com/learn/478/?ref=app

Answer 2

I discovered is Ruby-like...