求简单的JAVA小程序的源代码

《Java就业培训教程》P34源码
程序清单：Promote.java
class Promote
{
public static void main(String args[])
{
byte b = 50;
char c = 'a';
short s = 1024;
int i = 50000;
float f = 5.67f;
double d = .1234;
double result = (f * b) + (i / c) - (d * s);
System.out.println((f * b) + " + " + (i / c) + " - " + (d * s));
System.out.println("result = " + result);
}
}

《Java就业培训教程》P35源码
程序清单：TestScope.java
public class TestScope
{
public static void main(String[] args)
{
int x = 12;
{
int q = 96; // x和q都可用
System.out.println("x is "+x);
System.out.println("q is "+q);
}
q = x; /* 错误的行，只有x可用， q 超出了作用域范围 */
System.out.println("x is "+x);
}
}

《Java就业培训教程》P37源码
程序清单：TestVar.java