java - javafx 项目中的新类在尝试添加 if 语句时出现错误

Question

在使用 if 语句时，我不断收到“- token “;”上的语法错误，{预期在此 token 之后”错误消息。我不知道为什么，我对 java 有点陌生。这是一个 java fx 项目，但我还没有到 Controller 的连接。

我尝试添加 else 语句并更改变量。 ive也尝试将声明和修改分开。

package application;

public class Mathprocess {


    int numberOne = 15;
    int numberTwo = 5;
    int answerNumbers;
    int ansSubtract = 0;
    int ansDivide =  0;
    int ansMultiply = 0;
    int ansAddition = 0;




    //Question 1
    ansAddition = numberOne + numberTwo;
        String questionOne = numberOne + " + " + numberTwo +" = ";
    //Question 2 
    ansMultiply = numberOne * numberTwo;
    String questionTwo = numberOne + " * " + numberTwo +" = ";

    //Question 3 
    ansDivide = numberOne / numberTwo;




    //Question 4
    ansSubtract = numberOne - numberTwo;
    // error happens here
    if (ansAddition > 0) { 
        answerNumbers = ansAddition;
    }

}

预期的结果是一个干净的程序，没有错误。

Answer 1

您需要将代码移至方法内。解决方案之一可能如下

package application;
public class Mathprocess {

    public static void main(String[] args){

        int numberOne = 15;
        int numberTwo = 5;
        int answerNumbers;
        int ansSubtract = 0;
        int ansDivide =  0;
        int ansMultiply = 0;
        int ansAddition = 0;




        //Question 1
        ansAddition = numberOne + numberTwo;
        String questionOne = numberOne + " + " + numberTwo +" = ";
        //Question 2
        ansMultiply = numberOne * numberTwo;
        String questionTwo = numberOne + " * " + numberTwo +" = ";

        //Question 3
        ansDivide = numberOne / numberTwo;




        //Question 4
        ansSubtract = numberOne - numberTwo;
        // error happens here
        if (ansAddition > 0) {
            answerNumbers = ansAddition;
        }
    }


}

但是，它可能会根据您的需求而有所不同。