One of the Java 7 features introduced in jdk 1.7 is underscores in numeric literals. You can place underscores between digits of any numeric literal like int, byte, short, float, long, double. Using underscores in numeric literals will allow you to divide them in groups for better readability. This will provide the batter understanding of the code pieces.
Here we see through example the use of underscores in numeric literals :-
package r4rjdk7;
public class UnderscoreNumericLiterals {
public static void main(String[] args) {
long ccNumber = 1234_5678_9012_3456L;
long ssn = 999_99_9999L;
float pi = 3.14_15F;
long hexadecimalBytes = 0xFF_EC_DE_5E;
long hexadecimalWords = 0xCAFE_BABE;
long maxOfLong = 0x7fff_ffff_ffff_ffffL;
byte byteInBinary = 0b0010_0101;
long longInBinary = 0b11010010_01101001_10010100_10010010;
int add = 12_3 + 3_2_1;
System.out.println("ccNumber="+ccNumber);
System.out.println("ssn="+ssn);
System.out.println("pi="+pi);
System.out.println("hexadecimalBytes="+hexadecimalBytes);
System.out.println("hexadecimalWords="+hexadecimalWords);
System.out.println("maxOfLong="+maxOfLong);
System.out.println("byteInBinary="+byteInBinary);
System.out.println("longInBinary="+longInBinary);
System.out.println("add="+add);
}
}