//jdk 1.7 version Concept:----------------------

//Underscores Between Digits in Numeric Literals

package govind;

public class UnderScorePass {

                public static void main(String[] args) {

                                int carloan=10_00_00_00;

                                int homeloan=10_0000_00_00;

                                System.out.println("Car Loan="+carloan);

                                System.out.println("Home Loan="+homeloan);

                                //String s1="12_12";

                                //int x=Integer.parseInt(s1);//error

                }

}

o/p:------------

Car Loan=10000000

Home Loan=1000000000

Underscores Between Digits in Numeric LiteralsUnderscores are permitted in numeric literals.

 You can place underscores where you feel required to increase readability

 like between hundreds and thousands, thousands and lakhs etc.

This is used to group numbers in a bigger literal value (especially of long data type).

Note: Do not place underscore at the beginning or ending of the literal value.

Note: But following does not work (cannot parse with underscores).

//String s1="12_12";

//int x=Integer.parseInt(s1);//error

The above parsing raises NumberFormatException.