JAVA初学笔记---控制台输入：错误scanner

源代码

——————

public class scanner

{

public static void main(String[] args)

{

Scanner input = new Scanner(System.in);

System.out.print("Enter a number in radius: ");

double radius = input.nextDouble();

double area = radius * radius * 3.14159;

System.out.println("The area for the cicle of radius " +

radius + "is " +area );

}

}

此项程序遇到的错误

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Exception in thread “main” java.lang.Error: Unresolved compilation problems:

Scanner cannot be resolved to a type

Scanner cannot be resolved to a type

at 从控制台读取.scanner.main(scanner.java:7)

解决方案

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*缺少

import java.util.Scanner ;

在第一行记入即可

因为Scanner属于util包

所以需要导入util包*