Quiz

1. Let i, j be two integers. Write a program to exchange their values. How can you show your program is correct.


2. The identifier BufferedReader is normally abbreviated as BR in programming language C. However, Java programmers normally do not use abbreviations for identifiers. What are the advantages and disadvantages of not using abbreviations?

因為C語言發展的比JAVA早，在當時記憶體很貴，所以需要用abbreviation 來減少記憶體的使用.

advantage:
讓Java 的 programmers 可以很容易的去改變記憶體的內容值。

disadvantage:
需要用到很大的記憶體。