java - 如何在另一个方法中调用类内的构造函数

Question

我是一名学生。刚刚收到一份家庭作业，指出我应该调用构造函数方法而不是重用相同的代码。我复制了代码，因为我无法在没有错误的情况下调用构造函数。从单独的方法调用构造函数方法的正确语法是什么？

我确实进行了搜索，但找不到这个特定的(在类(class)内)问题。我确实尝试过使用“this”并创建一个类实例，但我不断收到错误。

import java.util.Random;
public class Coin {

    // variable for a generic coin toss
    private String sideUp;  

    // Constructor 

    // ******************** Instructor notes...
    // This is the same code as your toss() method
    // It is OK to call that method from your constructor.
    // Don't copy/paste code or repeat yourself if not required.
    public Coin() { 
        Random rand1 = new Random();
        int x = rand1.nextInt(2);   
        if (x > 0){
            sideUp = "Heads";
        }else{
            sideUp = "Tails";
        }
    }


    //Void Method
    public void toss() {
        // how to call the Coin constructor above??????????????????????????
        Coin();
    } 
}

Answer 1

反之亦然。将代码移回 toss 方法，然后从构造函数内部调用 toss() 。

import java.util.Random;
public class Coin {

   // variable for a generic coin toss
   private String sideUp;  

   // Constructor 

   // ******************** Instructor notes...
   // This is the same code as your toss() method
   // It is OK to call that method from your constructor.
   // Don't copy/paste code or repeat yourself if not required.
   public Coin() { 
       toss();  
   }


   //Void Method
   public final void toss() {
       Random rand1 = new Random();
       int x = rand1.nextInt(2);   
       if (x > 0){
           sideUp = "Heads";
       }else{
           sideUp = "Tails";
       }
   } 
}

正如其他评论和答案中指出的那样，调用可能从构造函数重写的方法是一个坏主意。这里有一个很好的解释:Why is it considered bad practice to call a method from within a constructor?

您可以像我在这里所做的那样将该方法设置为final以避免出现问题。