使用 java setter 和 getter 请求用户输入
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Asking for user input with java setters and getters
提问by T. Wielgos
how would i ask the user for the radius? I'm pretty sure it will be an easy fix but i'm just not sure how to do it. Here is my code so far.
我将如何向用户询问半径？我很确定这将是一个简单的修复，但我不确定如何去做。到目前为止，这是我的代码。
import java.util.Scanner;
public class CircleDriver
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
Circle circle1 = new Circle();
circle1.setRadius(20);
System.out.println("Enter the radius of a circle " + circle1.getRadius());
System.out.println("Area = " + circle1.calculateArea());
System.out.println("Diameter = " + circle1.calculateDiameter());
System.out.println("Circumference = " + circle1.calculateCircumference());
}
}
Circle class :
圈类：
public class Circle
{
private double radius;
private final double PI = 3.14159;
/**
* this method calculates the area of the given radius
* @return
*/
public double calculateArea() {
double area;
area = (PI * radius * radius);
return area;
}
/**
* this method calculates the diameter of the given radius
* @return
*/
public double calculateDiameter() {
double diameter;
diameter = (radius * 2);
return diameter;
}
/**
* this method calculates the circumference of the given radius
* @return
*/
public double calculateCircumference() {
double circumference;
circumference = (2 * PI * radius);
return circumference;
}
/**
* this method sets the radius of the object
* @param radius
*/
public void setRadius(double radius) {
this.radius = radius;
}
/**
* this radius returns the radius given
* @return
*/
public double getRadius() {
return radius;
}
}
回答by Andreas
You're creating a Scanner called input, but you're not using it. Instead, you're hard-coding the value 20.
您正在创建一个名为 的扫描仪input，但您并未使用它。相反，您正在对 value 进行硬编码20。
Try this:
试试这个：
Scanner input = new Scanner(System.in);
Circle circle1 = new Circle();
System.out.print("Enter the radius of a circle: ");
circle1.setRadius(input.nextDouble());
System.out.println("Area = " + circle1.calculateArea());
System.out.println("Diameter = " + circle1.calculateDiameter());
System.out.println("Circumference = " + circle1.calculateCircumference());
回答by Yassin Hajaj
Try this :
试试这个 ：
System.out.println("Enter the radius pls :");
try {
circle1.setRadius(input.nextDouble());
} catch (InputMismatchException e){
System.out.println("ERROR : Invalid input !");
}
回答by sre parthiban
Scanner input = new Scanner(System.in);
Circle circle1 = new Circle();
System.out.println("Enter the radius of a circle ");
int radius = input.nextInt();
There are several ways in getting an input from the user including BufferedReader, Console, Scanner etc. Above is an example using Scanner class. Now use the above radius value in your further calculations.
有多种方法可以从用户那里获取输入，包括 BufferedReader、Console、Scanner 等。以上是使用 Scanner 类的示例。现在在进一步计算中使用上述半径值。
