如何在Java中使用Scanner的nextLine方法

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英文:

How to use nextLine for scanner in java

问题

我使用了正确的数据类型,但是找不到错误。以下是我的代码:

Scanner input = new Scanner(System.in);

// 读取
System.out.printf("输入加油站:");
String s = input.nextLine();

System.out.printf("输入升数:");
double q = input.nextDouble();

input.nextLine(); // 读取换行符

System.out.printf("输入汽油类型:");
String t = input.nextLine();

System.out.printf("输入汽油价格:");
double p = input.nextDouble();

System.out.printf("输入折扣:");
int d = input.nextInt();

当我运行我的程序时,它不会进入下一行以输入值。对于汽油类型,我想要输入类似于 "Super 99" 这样的内容,所以我需要使用 input.nextLine(),但它没有起作用。

英文:

I used correct data type but I cant find my errors. Below is my code;

Scanner input = new Scanner (System.in);
	
	//Read 
	System.out.printf ("Enter the station: ");
	String s  = input.nextLine();
	
	System.out.printf ("Enter quantity in liter: ");
	double q  = input.nextDouble();

	
	System.out.printf ("Enter type of petrol: ");
	String t  = input.nextLine();
	
	System.out.printf ("Enter price of petrol: ");
	double p  = input.nextDouble();
	
	System.out.printf ("Enter discount: ");
	int d  = input.nextInt();

when I run my program, It does not go to next line to input values. For petrol type, I want to input something like "Super 99" so I need to use input.nextLine() but its not working.

如何在Java中使用Scanner的nextLine方法

答案1

得分: 0

尝试以下代码。

double q = input.nextDouble(); 这一行之后再加一行 input.nextLine();

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);

    // 读取
    System.out.printf("输入加油站:");
    String s = input.nextLine();

    System.out.printf("输入升数:");
    double q = input.nextDouble();
    input.nextLine();

    System.out.printf("输入油品类型:");
    String t = input.nextLine();

    System.out.printf("输入油价:");
    double p = input.nextDouble();

    System.out.printf("输入折扣:");
    int d = input.nextInt();
}
英文:

Try the below code.

Use another input.nextLine() right after the double q = input.nextDouble(); line.

public static void main(String[] args) {
        Scanner input = new Scanner (System.in);

        //Read
        System.out.printf ("Enter the station: ");
        String s  = input.nextLine();

        System.out.printf ("Enter quantity in liter: ");
        double q  = input.nextDouble();
        input.nextLine();

        System.out.printf ("Enter type of petrol: ");
        String t  = input.nextLine();

        System.out.printf ("Enter price of petrol: ");
        double p  = input.nextDouble();

        System.out.printf ("Enter discount: ");
        int d  = input.nextInt();
    }

答案2

得分: 0

/*
*****这将对您有效
*/

import java.util.*;

class Tester {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.printf("输入加油站:");
        String s = input.nextLine();

        System.out.printf("输入升数:");
        double q = input.nextDouble();

        input.nextLine();
        System.out.printf("输入汽油类型:");
        String t = input.nextLine();

        System.out.printf("输入汽油价格:");
        double p = input.nextDouble();

        System.out.printf("输入折扣:");
        int d = input.nextInt();
    }
}
英文:

/*
*****This will work for you dear
*/

import java.util.*;
class Tester
{

    public static void main(String[] args)
  {
    Scanner input = new Scanner (System.in);
    System.out.printf ("Enter the station: ");
    String s  = input.nextLine();
    
    System.out.printf ("Enter quantity in liter: ");
    double q  = input.nextDouble();

    input.nextLine();
    System.out.printf ("Enter type of petrol: ");
    String t  = input.nextLine();
    
    System.out.printf ("Enter price of petrol: ");
    double p  = input.nextDouble();
    
    System.out.printf ("Enter discount: ");
    int d  = input.nextInt();
   }

}

答案3

得分: -1

你只需要使用:

System.out.println("输入汽油类型");

它将像这样工作:

输入汽油类型
Super99     //根据您的选择在此输入,光标将自动移到下一行
英文:

You just need to use:

System.out.println("Enter the type of petrol");

It will work like this :

Enter the type of petrol
Super99     //its what you will enter as per your choice here the cursor will automatically take you to the next line

答案4

得分: -1

要打印包括换行符在内的一行内容:

```java
System.out.println("输入汽油价格:");
// -OR-
System.out.printf("输入汽油价格:\n");

获取单个标记(单词、数字、整数等):

scanner.nextInt(); // 整数
scanner.next(); // 单词

获取整行内容:

scanner.useDelimiter("\r?\n");
// 现在扫描器处于“整行”模式
scanner.nextInt(); // 仍然有效
scanner.next(); // 获取一行的内容

要返回到“每个空白字符一个标记”的模式,在此模式下,输入例如 "a b c"(按Enter键)将导致有3个 .next() 调用的数据可用:

scanner.reset();
// -OR-
scanner.useDelimiter("\\s+");

提示:不要混合使用 nextLine() 和任何其他 next 方法。


<details>
<summary>英文:</summary>

To print a line _including_ a newline:

System.out.println("Enter price of petrol: ");
// -OR-
System.out.printf("Enter price of petrol: \n");


To obtain a single token (a single word, number, integer, etc):

scanner.nextInt(); // integer
scanner.next(); // word


To obtain an entire line:

scanner.useDelimiter("\r?\n");
// now the scanner is in 'entire line' mode
scanner.nextInt(); // still works
scanner.next(); // gets one line's worth


To go back to &#39;one token per whitespace&#39; mode, where entering e.g. &quot;a b c&quot; (enter) will cause 3 `.next()` calls of data to be available:

scanner.reset();
// -OR-
scanner.useDelimiter("\s+");


TIP: Don&#39;t mix `nextLine()` and any other `next` method.


</details>



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  • 本文由 发表于 2020年7月27日 14:41:26
  • 转载请务必保留本文链接:https://go.coder-hub.com/63109936.html
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