Java Scanner nextBoolean() 方法

2024 年 11 月 6 日 | 阅读 2 分钟

nextBoolean() 是 **Java Scanner** 类的一个方法，用于将输入的下一个标记扫描为一个布尔值并返回该值。如果扫描成功，则跳过已匹配的输入。

语法

以下是 **nextBoolean()** 方法的声明

参数

此方法不接受任何参数。

返回值

nextBoolean() 方法返回从输入中扫描到的布尔值。

异常

InputMismatchException - 如果下一个标记不是有效的布尔值，则会抛出此异常。

NoSuchElementException - 如果输入耗尽，将抛出此异常。

IllegalStateException - 如果在 Scanner 关闭后调用，则会抛出此异常。

兼容版本

Java 1.5 及以上版本

示例 1

import java.util.*;
public class ScannerNextBooleanExample1 {  
	public static void main(String[] args) {       
           System.out.print("Are you above 18?- ");
           Scanner sc = new Scanner(System.in);
           boolean bn = sc.nextBoolean();
           if (bn == true) {
               System.out.println("You are over 18");
           } else if (bn == false) {
               System.out.println("You are under 18");
           }
           sc.close();          	      
	 }
}

输出

Are you above 18?- True
You are over 18
Are you above 18?- False
You are under 18

示例 2

import java.util.*;  
public class ScannerNextBooleanExample2 {  
     public static void main(String args[]){ 
    	   String str = "Hello true World! 12 false 15 ";
         Float f = 2.123f;
         str = str + f;
         //Create a new scanner with string Object
         Scanner scanner = new Scanner(str);
         //Use US locale to be able to identify boolean in the string
         scanner.useLocale(Locale.US);
         //Find the next boolean token and print it
         while (scanner.hasNext()) {
            //Check if the next is a boolean, print found
            if (scanner.hasNextBoolean()) {
               System.out.println("Found Boolean:" + scanner.nextBoolean());
            }
            //If boolean is not found, print "Not Found"
            System.out.println("Not Found Boolean:" + scanner.next());
         }    
         scanner.close();
     }  
} 

输出

Not Found Boolean:Hello
Found Boolean:true
Not Found Boolean:World!
Not Found Boolean:12
Found Boolean:false
Not Found Boolean:15
Not Found Boolean:2.123

示例 3

import java.util.*;  
public class ScannerNextBooleanExample3 {  
     public static void main(String args[]){ 
    	 System.out.print("Would you like to play? : ");
    	 Scanner scan = new Scanner(System.in);
    	 if(scan.nextBoolean()==true) {
    		System.out.println("Great! This will be fun.");
    	 }else {
    		System.out.println("Maybe next time");
    	 }
    	 scan.close();
     }  
} 

输出

Would you like to play? : True
Great! This will be fun.

Would you like to play? : False
Maybe next time

下一话题Java-scanner-nextbyte-method

← prev next →

Java Scanner nextBoolean() 方法

语法

参数

返回值

异常

兼容版本

示例 1

示例 2

示例 3

联系信息

关注我们

教程

面试题

在线编译器

Python

Java

.Net Framework

AI, ML and Data Science

Cloud Technology

B.Tech and MCA

Web Technology

PHP

Software Testing

Technical Interview

Java Interview

Python

Web Interview

Database Interview

B.Tech / MCA

Important Interview

Software Testing Interview

Company Interviews

Online Compilers

Multiple Choice Questions

Java EnumMap

Java DriverManager

Java ThreadLocal

Java StringBuilder

Java StringBuffer

Java Short

Java Float

Java HashSet

Java ThreadLocalRandom

Java ThreadGroup

Java Double

Java Throwable

Java PriorityQueue

Java Matcher

Java 方法

Java 枚举

Java TreeSet

Java TimeZone

Java System

Java Locale

Java Scanner

Java Random

Java Currency

Java Character

Java Timertask

Java Timer

Java Process

Java Calendar

Java Scanner nextBoolean() 方法

语法

参数

返回值

异常

兼容版本

示例 1

示例 2

示例 3

相关帖子

Java Scanner delimiter() 方法

Java Scanner nextFloat() 方法

Java Scanner useDelimiter() 方法

Java Scanner close() 方法

Java Scanner ioException() 方法

Java Scanner useLocale() 方法

Java Scanner match() 方法

Java Scanner hasNextInt() 方法

Java Scanner hasNextByte() 方法

Java Scanner next() 方法

订阅 Tpoint Tech

联系信息

关注我们

教程

面试题

在线编译器