Homework 9/21/2007

1. Explain bytecode, JVM
Byte-Code:將所寫的程式轉換成機械語言。
JVM:Java Virtual Machine,that is a Java byte-code interpreter.

2. Explain class, object
Class是用來描述屬性(Property)跟方法(Method)，class要宣告成物件才能 呼叫Method， Object包含屬性(Property)和方法(Method)，object可以直接 呼叫其方法，不需要宣告即可。

4.1 Write a Java program as follows:

Let i=2;
Print i;
Print 2 * (i++);
Print i;

Ans: 2, 4, 3

4.2 Write a Java program as follows:

Let i=2;
Print i;
Print 2 * (++i);
Print i;

Ans: 2, 6, 3

4.3 Write a Java program as follows:

Let m=7, n=2;
Print (double) m/n;
Print m/ (double)n;

Ans: 3.5, 3.5