在java中添加UnsignedInteger并继续获得预期的方法调用

Question

我不断收到方法调用预期错误。我不知道我能做什么。有没有人知道我们如何在不改变它的情况下进行主要运行？尝试了几个小时不同的方法，但无法弄清楚。public class UnsignedInteger {  public static void main(String[] args){    UnsignedInteger three = new UnsignedInteger(3); // 3 is "autoboxed"    UnsignedInteger four = new UnsignedInteger(4); // 4 is "autoboxed"    UnsignedInteger sum = three.add(four);    System.out.println(sum); // Should print 7    try    {        UnsignedInteger broken = new UnsignedInteger(-1);    }    catch(IllegalArgumentException e)    {        System.out.println("Negative values are not allowed");     }int val;// This is the constructor. It should throw an IllegalArgumentException if a //negative value is passed inpublic UnsignedInteger(Integer value){   if(value<0){      throw new IllegalArgumentException("You have entered a negative number.");    val=value;   }}// This method will return the Integer that was passed in via the constructor.public Integer getRawInteger(){    return val;}// Return the sum of the value stored in this object with the object passed as a parameter (i.e., otherUint)// This should not mutate the state of our class.public UnsignedInteger add(UnsignedInteger otherUint){   return  getRawInteger(this.add(getRawInteger()));    }}

Answer 1

public UnsignedInteger(Integer value) 是一个构造函数，但您试图在此处将其作为方法调用：

return UnsignedInteger(getRawInteger());

和这里：

return UnsignedInteger();

要调用构造函数，您应该编写：

return new UnsignedInteger();

此外，public UnsignedInteger(Integer value)构造函数不应该有 return 语句，因为构造函数不返回值。

此外，getRawInteger应该返回一个Integer，但您返回的是一个UnsignedInteger。