JPMorganChase Associate Developer interview questions

I met a technical team in career fair. They asked me about my project and past experience. It was on sql/nosql databases. I was asked to write a program to simulate Calculator. They were basically looking for the knowledge of design patterns. I was asked to talk about the output of a function. It was related to pass by copy/value. After this I was called for an onsite interview. It was 4 30 min long interviews. But it went over. They were very nice.