Agent IQ interview questions

Despite being over a year ago, this interview still sticks out in my mind as one of the most frustrating. It was a fairly typical onsite interview, with multiple interviews coming in at different points with different questions. There were questions about systems design and algorithm puzzles. At one point, I was solving an algorithm question (can't remember the question) and one of the interviewers asked me why I was using a for-loop instead of forEach to iterate through a string. I replied that strings do not have a forEach method (it's an array method), but the interviewer told me I was wrong without verifying their info. I conceded, but later confirmed that I was correct when I got home. During the same problem, that interviewer seemed to become exasperated and laughed while I was writing on the whiteboard.