1.Java分支结构之 if...else
package step2;

import java.util.Scanner;

public class HelloIfStep2 {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		/******start******/
        int score;
		System.out.println("请输入学员成绩：");
		score=input.nextInt();
        if(score>=85 && score<=100) 
        {
        System.out.print("优，非常棒！");
        }
        else 
        {
        System.out.print("良，下次加油！");
        }
        
		
		
		
		/******end******/
	}
}
2.Java分支结构之Switch
package step4;

import java.util.Scanner;

public class HelloSwitch {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		System.out.println("请输入月份：");
		
		int input = sc.nextInt();	//获取输入的月份
		
        //通过输入的月份来判断当前季节并输出
		/*****start*****/
		int season;
        switch(input)
        {
            case 1:
            System.out.print("1月是冬天");
            break;
            case 2:
            System.out.print("2月是冬天");
            break;
            case 3:
            System.out.print("3月是春天");
            break;
            case 4:
            System.out.print("4月是春天");break;
            case 5:
            System.out.print("5月是春天");
            break;
            case 6:
            System.out.print("6月是夏天");
            break;
            case 7:
            System.out.print("7月是夏天");
            break;
            case 8:
            System.out.print("8月是夏天");
            break;
            case 9:
            System.out.print("9月是秋天");
            break;
            case 10:
            System.out.print("10月是秋天");
            break;
            case 11:
            System.out.print("11月是秋天");
            break;
            case 12:
            System.out.print("12月是冬天");
            	break;
        }

		
		/*****end*****/
		
	}
}
3.Java分支结构之多重if
package step3;

import java.util.Scanner;

public class HelloStep3 {
	public static void main(String[] args) {
		System.out.println("星级成绩评定系统");
		System.out.println("请输入成绩：");
		Scanner sc = new Scanner(System.in);
		/******start******/
     int score;
        score=sc.nextInt();
        if(score>=90&&score<=100)
        {
            System.out.print("*****五星成绩");
        }
        else if(score<90&&score>=80)
        {
            System.out.print("****四星成绩");
        }
		else if(score<80&&score>=70)
        {
            System.out.print("***三星成绩");

        }
		else if(score<70&&score>=60)
        {
            System.out.print("**俩星成绩");
        }
        else if(score<60)
        {
            System.out.print("无星成绩");
        }
		
		
		
		
		/******end******/
	}
}
4.来吧，我是BOSS！
package step5;

import java.util.Scanner;

public class Practice {
    
    	final static Scanner sc = new Scanner(System.in);	//创建扫描仪

		//第一题
		public void first(){
			System.out.println("请输入人数：");
            int input = sc.nextInt();		//获取输入的数据
            
			/*****start*****/
			
			 if (input<10)
             {
                System.out.println("打半场");
            }
            else
            {
                System.out.println("打全场");
            }
			
			
			
			/*****end*****/
		}
		
		//第二题
		public void second(){
			System.out.println("请输入今天星期几：");
            int input = sc.nextInt();		//获取输入的数据
            
			/*****start*****/
 if (input==1)
 {
                System.out.println("今天吃米饭");
            }
            else if(input==2) 
            {
                System.out.println("今天吃牛排");
            }
            else if(input==3) 
            {
                System.out.println("今天吃鸡排");
            }
            else
            {
                System.out.println("今天吃红烧肉");
            }

			

			
			/*****end*****/
		}	
		
		//第三题
		public void third(){
			System.out.println("请输入今天星期几：");
            int input = sc.nextInt();		//获取输入的数据
            
			/*****start*****/
            switch (input)
            {
                case 1:
                System.out.println("今天吃米饭");
                break;
                case 2:
                System.out.println("今天吃牛排");
                break;
                case 3:
                System.out.println("今天吃鸡排");
                break;
                default:
                System.out.println("今天吃红烧肉");
                break;
                
            }

			
			
			/*****end*****/
		}
}