“，”上的错误考虑添加 "Expression"

Question

我正在尝试为我妹妹制作一个小型数学游戏，截至目前，我有一个 class 难度级别和一个练习题。但是当我尝试在第 4 行设置难度级别时，我得到 "Error on "，“考虑添加 "Expression"”。这是什么意思，我该如何解决？我正在使用 Processing 3.5.4

  background(#FFFFFF);
  size(1280, 720);
  DifficultyLevel easy = new DifficultyLevel(10, ['+']);
}

class DifficultyLevel {
  int maxNumber;
  Character[] allowedOperators;

  DifficultyLevel (int mN, Character[] aO) {
    maxNumber=mN+1;
    allowedOperators=aO;
  }

  Exercise generateExcercise() {
    return new Exercise((int) random(maxNumber), (int) random(maxNumber), allowedOperators[(int) random(allowedOperators.length)]);
  }
}

class Exercise {
  int numberOne;
  int numberTwo;
  Character operator;

  Exercise(int one, int two, Character op) {
    numberOne=one;
    numberTwo=two;
    operator=op;
    if (numberOne < numberTwo && op=='-') {
      numberOne=numberOne+numberTwo;
      numberTwo=numberOne-numberTwo;
      numberOne=numberOne-numberTwo;
    }
  }

  boolean checkResult(float in) {
    float res=0;
    switch(operator) {
    case '+':
      res = numberOne + numberTwo;
      break;
    case '-':
      res = numberOne - numberTwo;
      break;
    case '·':
      res = numberOne * numberTwo;
      break;
    case '÷':
      res= numberOne / numberTwo;
    }
    return res==in;
  }
}

对了，我知道生成习题的代码不好，以后会改进的

Answer 1

表达式语句 DifficultyLevel easy = new DifficultyLevel(10, ['+']); 在语法上不正确。

您必须创建一个字符数组

Character[] charArray = {'+'};

终于可以使用数组了：

DifficultyLevel easy = new DifficultyLevel(10, charArray);

“，”上的错误考虑添加 "Expression"

Error on "," Consider adding "Expression"

processing