Infosys Junior Java Developer interview questions

Interview very polite & she asked me first about my self & then started the java OOP question like Abstration, Inheritance, Polymorphism, Encapsulation etc,then she asked some question related to Java Design Pattern I was unable to answer those question & said sorry for this question & last question asked by the recruiter is related to why Array Index always start with 0

Verry easy and smoothly asking questions from core to advance java. Then some questions on spring boot and database like sql joins highest second salry. Hashmap internl working. Difference between arrayList and linked list