Question

在使用if语句时，我不断收到“-令牌“;”上的语法错误，{预期在此令牌之后“错误消息。我不确定为什么，我对java有点陌生。这是一个Java fx项目，但我与控制器没有任何连接。

ive尝试添加else语句并更改变量。香港专业教育学院还试图将声明和修改分开。

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;
    }

}

预期结果是干净的程序，没有错误。

Answer 1

您需要在方法内部移动代码。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要而有所不同。

Answer 2

您的问题是，在Java中，每个操作都应在方法内部处理。尝试这样的事情：

public void actions() { //declaring a method
    ansAddition = numberOne + numberTwo;
    String questionOne = numberOne + " + " + numberTwo + " = ";

    ansMultiply = numberOne * numberTwo;
    String questionTwo = numberOne + " * " + numberTwo + " = ";


    ansDivide = numberOne / numberTwo;


    ansSubtract = numberOne - numberTwo;

    if (ansAddition > 0) {
        answerNumbers = ansAddition;
    }
}

Answer 3

根据定义 班级： 一个类描述了属于它的对象的内容：它描述了数据字段的集合（称为实例变量），并定义了操作（称为方法）。

一个类包含2个实例变量和方法，因此，如果要放置其他东西，则必须借助方法

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
  method() {
    if (ansAddition > 0) {
      answerNumbers = ansAddition;
    }
  }

}

Answer 4

您需要在诸如“打包应用程序”之类的函数中执行代码；

public class Mathprocess {


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




   public static void main(String[] args)
   {
        //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;
    }
    }

}`

尝试添加if语句时，javafx项目中的新类给出错误

4 个答案: