package org.circle;class Area
{ public static void main(String[] args)
{
final double PI = 3.1415;
double r; area;
r = 3;
area = PI * r * r;
System.out.println("圆的面积="+area);
}}
{ public static void main(String[] args)
{
final double PI = 3.1415;
double r; area;
r = 3;
area = PI * r * r;
System.out.println("圆的面积="+area);
}}
{
public static void main(String[] args)
{
final double PI = 3.1415;
double r, area;//here!!
r = 3;
area = PI * r * r;
System.out.println("圆的面积=" + area);
}
}
{final double PI = 3.1415;
double r; area;
r = 3;
area = PI * r * r;
System.out.println("圆的面积="+area);
}定义多个变量时,变量中间用逗号隔开而不是分号;