第四周作业-键盘输入数据 和 数据类型

public class ComputerArea
{
public static void main(String args[]){
final double PI=3.14159;
double area;
area =PI*10*10;
System.out.println("The area for the circle of 10 is"+area);
}
}

import java.util.Scanner;
public class ComputerArea2
{
public static void main(String args[]){
final double PI=3.14159;
double area;
double radius =0.0;
//输出提示符
System.out.println("请输入一个浮点数(如果数字<=0,则结束)");
Scanner sc =new Scanner(System.in);
while(sc.hasNextDouble()){
radius=sc.nextDouble();
//请输入double数值，如果<=0,则结束
if(radius<=0)
break;
//计算圆面积
area =PI*radius*radius;
System.out.println("The area for the circle is"+area);
//输出提示符
System.out.println("请输入一个浮点数(如果数字<=0,则结束)");
}
System.out.println("程序计算结束");
}
}

public class MathDemo {
public static void main(String area[]){
System.out.println("abs(-5)="+Math.abs(-5));
System.out.println("max(6.75,3.14)="+ Math.max(6.75,3.14));
System.out.println("min(100,200)="+ Math.min(100,200));
System.out.println("round(3.5)="+Math.round(3.5));
System.out.println("sqrt(2)="+Math.sqrt(2));
System.out.println("pow(2,5)="+Math.pow(2,5));
System.out.println("E="+Math.E);
System.out.println("exp(2)="+Math.exp(2));
System.out.println("log()2="+Math.log(2));
System.out.println("ceil(6.75)="+Math.ceil(6.75));
System.out.println("floor(6.75)="+Math.floor(6.75));
System.out.println("Pi="+Math.PI);
System.out.println("sin(Pi/4)="+Math.sin(Math.PI/4));
System.out.println("cos(1)="+Math.cos(1));
}
}