如何在Java中实现输入与结构的高效处理？

输入

1. 用next方式接收

   package com.kuang.scanner;import java.sql.SQLOutput;
   import java.util.Scanner;public class Demo01 {public static void main(String[] args) {//创建一个扫描器，用于接收键盘数据Scanner scanner = new Scanner(System.in);System.out.println("使用next方式接收：");//判断用户有没有输入字符串if (scanner.hasNext()){//使用next方式接收String str = scanner.next();System.out.println("输出的内容为："+str);}//凡是属于IO流的类如果不关闭会一直占用资源，要用完就关scanner.close();}
   }

2. 用nextline方式接收

   package com.kuang.scanner;import java.util.Scanner;public class Demo02 {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);System.out.println("使用nextLine方式接收");if(scanner.hasNextLine()){String str=scanner.nextLine();System.out.println("输出内容为："+str);}scanner.close();}
   }

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if语句

1. 单选择结构

   package com.kuang.struct;import java.util.Scanner;public class IfDemo01 {public static void main(String[] args) {//单选择结构Scanner scanner = new Scanner(System.in);System.out.println("请输入：");String str=scanner.nextLine();if(str.equals("Hello")){System.out.println(str);}System.out.println("End");scanner.close();}
   }

2. 双选择

   package com.kuang.struct;import java.util.Scanner;public class IfDemo02 {public static void main(String[] args) {//双选择结构Scanner scanner = new Scanner(System.in);System.out.println("输入成绩：");double score= scanner.nextDouble();if(score>=60){System.out.println("及格");}else {System.out.println("不及格");}scanner.close();}
   }

3. 多选择

   package com.kuang.struct;import java.util.Scanner;public class IfDemo03 {public static void main(String[] args) {//多选择结构Scanner scanner = new Scanner(System.in);int score = scanner