January 10, 2018, Wednesday, Beijing, sunny, with a minimum temperature of minus 11 degrees
Company interviewed today
1. Nash Space
2. Palm gold clothing
3. Sparkle Roll Wealth Management Co., Ltd.
4. Pintec Group
Today's interview questions
1. A=10, B=20, how to exchange these 2 numbers so that A=20, B=10? Write a specific algorithm? (2 numbers want to add or subtract)
2.mysql has several kinds of indexes, such as the combined index index(a,b,c), will the index of b be used?
3. What are the collection classes of java? Which is in order? How to ensure it is in order?
4. What transaction isolation levels does the database have?
5. What is the result of hashset storage?
6. How is the treemap sorted? What is the time complexity?
7. Will the allowdefinition be rolled back if an exception is thrown?
8. How to throw stack exception?
9. How many bytes does the long type occupy?
10. How is the bottom layer of the equals method of Object implemented?
11. What is the difference between where and having, and the difference between in and exits in SQL?
12. What are the mysql storage engines and what are their characteristics?
13.What are the weaving methods of spring apo section?
14. What methods can implement distributed locks?
15. The principle and practical application of reflection?
16. How does java implement polymorphism?
17. Which packages of java are used? What is the difference between nio and bio?
18. How to facilitate hashset and what is the time complexity?