Question

在mousePressed中，我需要aNumber的值，但是我不能通过mousePressed（int aNumber）..所以当通过javascript调用Numbers时我需要某种全局来保持修改..

int number = 0;
int theNumbers(int aNumber) { //aNumber = 1, 2, or 3, from the javascript)

  println(number); // prints the correct number
  int number = aNumber; // set the global variable number equal to aNumber 
  return number;
}

void mousePressed() {
  aLongNumber = 10000000000;

  println(number); // prints 0 right now, should print the value of aNumber
  long numberLong = aLongNumber + (number * aLongNumber);
}

Answer 1

您要在theNumbers()内声明局部变量，只需在int之前删除number，这样您的函数将如下所示：

int theNumbers(int aNumber) { //aNumber = 1, 2, or 3, from the javascript)

  println(number);
  number = aNumber; // removed int that made new local variable "number"
  return number;
}

Answer 2

删除此行：

 int number = aNumber;

您将参数复制到＆＃34;数字＆＃34;变量然后返回它。实际上，您正在打印全局变量＆＃34; number＆＃34;您在任何地方发布的代码中没有更改，然后返回参数，这与您刚刚完成的计算无关。

您可能想要修改全局参数number然后将其返回，因此请进行更改：

int theNumbers(int aNumber) {
   // calculations for number (based on aNumber? contains number=SOMETHING somewhere?)

   println(number); // prints the correct number    
   return number;
}

编辑：

然后修改全局。从int number = aNumber;中删除类型，这样就不会重新初始化变量。最后：

int theNumbers(int aNumber) {
   // calculations for number (based on aNumber? contains number=SOMETHING somewhere?)

   println(number); // prints the correct number    
   number = aNumber;
   return number;
}

使用函数修改全局变量？

2 个答案: