小柳在实训的第二天主要学到了Scanner, if..else.. ,if.. elseif.. else.., switch..case.., 循环语句(for, while ,do..while..)等。
1.Scanner (案例 物体下落距离)
public class IdentifyDemo01 {
//提示用户输入姓名和年龄
//键盘扫描器 创建Scanner
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
//提示用户输入姓名和年龄
// System.out.println("请输入你的姓名");
// String name = scanner.next();
//
// System.out.println("请输入你的年龄");
// int age = scanner.nextInt();
// System.out.println("姓名" + name + "年龄" + age);
//提示用户输入班级学号和座右铭
//
//求下落位移 用户输入下落时间
System.out.println("请输入下落时间:");
int time = scanner.nextInt();
System.out.println("下落位移为:");
double d = 0.5 * 9.8 * time * time;
System.out.println(d);
}
}
2.if..else (案例 最大值)
import java.util.Scanner;
public class Max {
public static void main(String[] args) {
//用户输入两个数求最大值
Scanner scanner = new Scanner(System.in);
System.out.println("请输入两个数:");
System.out.println("第一个数为:");
int a = scanner.nextInt();
System.out.println("第二个数为:");
int b = scanner.nextInt();
int max = a;
if(a<b) {
max = b;
}
System.out.println(max);
}
}
3.if.. elseif.. else..(案例 个人所得税的计算)
import java.util.Scanner;
public class Revenue {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入你的薪水:");
int money = scanner.nextInt();
if(money > 1 & money <= 5000) {
System.out.println("个人所得税为:0");
} else if (money > 5000 & money <= 8000) {
System.out.println("个人所得税为:" + money * 0.03);
} else if (money > 8000 & money <= 17000) {
System.out.println("个人所得税为:" + money * 0.1);
} else if (money >17000 & money <= 30000) {
System.out.println("个人所得税为:" + money * 0.2);
} else if (money > 30000 & money <= 40000) {
System.out.println("个人所得税为:" + money * 0.25);
} else if (money > 40000 & money <= 60000) {
System.out.println("个人所得税为:" + money * 0.3);
} else if (money > 60000 & money <= 85000) {
System.out.println("个人所得税为:" + money * 0.35);
} else {
System.out.println("个人所得税为:" + money + 0.45);
}
}
}
4.switch..case.. (案例 月份天数)
import java.util.Scanner;
public class SwitchDemo02 {
public static void main(String[] args) {
System.out.println("请输入一个月份:");
Scanner scanner = new Scanner(System.in);
int month = scanner.nextInt();
switch(month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
System.out.println(month + "月,有31天");break;
case 4:
case 6:
case 9:
case 11:
System.out.println(month + "月,有30天");
default:
System.out.println("二月有28天");
}
}
}
import java.util.Scanner;
public class SwitchCaseDemo {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入你的名次:");
int num = scanner.nextInt();
switch(num) {
case 1:
System.out.println("全球游玩");break;
case 2:
System.out.println("国外游玩");break;
case 3:
System.out.println("国内游玩");break;
case 4:
System.out.println("省内游玩");break;
default:
System.out.println("玩什么玩,加班");
}
}
}
5.for (案例 打印偶数)
public class ForDemo01 {
public static void main(String[] args) {
//打印0到10的数字
// for(int i = 1; i <= 10; i++) {
// System.out.println(i + " ");
// }
//打印0到100的偶数
for (int i = 0; i <100; i++) {
if(i % 2 == 0) {
System.out.println(i);
}
}
}
}
public class DoubleForDemo01 {
public static void main(String[] args) {
for (int i = 1; i <= 5; i++) {
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println();
}
}
}
6.while (案例 见下)
import java.util.Scanner;
public class WhileDemo02 {
public static void main(String[] args) {
//你可以跑几圈?
Scanner scanner = new Scanner(System.in);
int i =1;
while (true) {
System.out.println("你已经跑了第" + i + "圈,是否继续?");
String str = scanner.next();
if ("是".equals(str)) {
System.out.println("加油,加油! 正在跑第" + i + "圈");
i++;
} else if("否".equals(str)) {
System.out.println("不行了,跑不动了");
}
}
}
}
7.do..while..
public class DoWhileDemo {
public static void main(String[] args) {
//do{}while()循环至少执行一次
int i = 1;
do{
System.out.println(i + " ");
i++;
}while(i <=10);
}
}
很期待明天所学的内容!!