In this article, we will take a look on another interview question about adding two numbers, but without using + or ++ operator. Interview starts with a simple statement, Can you write a function to add two numbers (integers) without using + or plus arithmetic operator in Java? If you are good in maths, it wouldn’t take more than a second to say that, we can use subtraction or - operator to add two numbers because a-(-b)== a+b. Well that’s correct, but real question starts when interviewer quickly points out that, you can not use any arithmetic operator including +,-,*,/++ or --. Programming and Coding questions are integral part of any Java interview. You should always expect couple of questions like this, e.g. swapping two numbers without using temp variable. If you have been giving interviews, then you know that, it will eventually comes downs to bitwise operator in Java. Yes, we can add two numbers by using bitwise and bitshift operators, which is not arithmetic. Interviewer, will be happy by hearing bitwise operator, but he would like to see the code. Well, if you know binary arithmetic or how to add numbers in binary format, you may be familiar with fact than sum of two numbers can be obtained by using XOR operation and carry, by using AND operation. This is the fact, you must remember to solve this question or add two integers without using any arithmetic operator e.g. plus, minus etc. Sometime interviewer, may ask you to write both iterative and recursive solution of same question, Since recursion is another confusing programming technique, it's favored more during interviews. In this Java tutorial, we will see both recursive and iterative version of our add method, which calculate sum of two numbers without using arithmetic operator, but using bitshift and bitwise operators in Java.