java 实验一

步骤	耗时h	百分比%
需求分析	0.3h	7.5
设计	2.5h	62.5
代码实现	0.5h	12.5
测试	0,2h	5
分析总结	0.5h	12.5

实验一 截图

实验二：

实验三

实现四则运算

代码：

import java.util.Scanner;
public class D1_jisuanqi {
public static void main(String[] args){
double x,y,s;
int i;
System.out.println("1是乘法，2是除法，3是加法，4是减法，5是取模");
Scanner sc = new Scanner(System.in);
i = sc.nextInt();
if (i == 1)
{
System.out.println("你将用乘法");
System.out.println("请输入x,y两个值：(用空格间隔)");
Scanner c = new Scanner(System.in);
x = c.nextDouble();
y = c.nextDouble();
s = x*y;
System.out.println("x*y的值是："+s);
c.close();
}
else if (i == 2)
{
System.out.println("你将用除法");
System.out.println("请输入x,y的值：(用空格间隔)");
Scanner d = new Scanner(System.in);
x = d.nextDouble();
y = d.nextDouble();
s = x/y;
System.out.println("x/y的值是："+s);
d.close();
}
else if (i == 3)
{
System.out.println("你将用加法");
System.out.println("请输入x,y的值：(用空格间隔)");
Scanner e = new Scanner(System.in);
x = e.nextDouble();
y = e.nextDouble();
s = x+y;
System.out.println("x+y的值是："+s);
e.close();
}
else if(i == 4)
{
System.out.println("你将用减法");
System.out.println("请输入x,y的值：(用空格间隔)");
Scanner f = new Scanner(System.in);
x = f.nextDouble();
y = f.nextDouble();
s = x-y;
System.out.println("x-y的值是："+s);
f.close();
}
else
{
System.out.println("你将用取模");
System.out.println("请输入x,y的值(用空格间隔)");
Scanner g = new Scanner(System.in);
x = g.nextDouble();
y = g.nextDouble();
s = x%y;
System.out.println("x%y的值是："+s);
g.close();
}
sc.close();
}
}

package ljp;

import java.util.Scanner;

public class Hello {

public static void main(String[] agrs){

System.out.println("Input your first name,please:");

Scanner s =new Scanner(System.in);

String name = s.next();

System.out.println("Hello"+name+"!");

}