Momentive Software Software Developer (Java) interview questions

1)First inteviewer asked me to explain all technial skills and current domain. During the interview, interviewer showed me around 10 different code snippets and asked me to guess the output, these code snippets were related to basic java sytax and rules. 2)After that interviewer asked me to explain all principles of core java oops with real time example. 3)Types of iterator in java 4)Difference between fail fast and fail safe 5)Sql query for finding highest salary of employee 6)String manipulation program finding length of string without using .length and foreach loop. 7)Concurrent modification exception 8)Internal working of hashmap 9)collision 10)which java fearures do you use in your current project