Code reviews are an important way to catch issues early. The style and process of code review may very from person to person.
Sample answer is:
I like doing code reviews. It helps me in improving knowledge of business functionality as well as gives me insight into different ways of solving problems. Some of the important points during code review are:
I try not to associate an issue in code with a person. I give my comments in a humble way so that the other person takes these in positive manner.
If I do not understand an approach, I try to discuss with the developer to understand his/her point of view. I check for adherence to company policy and style guides for writing code.
I look at the code from performance perspective as well and try to give suggestions and improvements.