自定义函数

无参数函数

表现：无参数，无返回值

 void：表示为空，意为让其执行一系列的操作，没有返回值

圆括号：表示不需要任何的参数，

void displayClear()
{
        digitalWrite(3,HIGH);
        digitalWrite(4,HIGH);
        digitalWrite(5,HIGH);
        digitalWrite(6,HIGH);
        digitalWrite(7,HIGH);
        digitalWrite(8,HIGH);
        digitalWrite(9,HIGH);
}

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输入参数的函数

//RadomNumber传入函数，名称为LedNumber；
//然后进入switch-case语句进行运算
void loop() {
    int RadomNumber=random(0,5);
    displayNumber(RadomNumber);
    delay(10);
    displayClear();
    delay(10);
}

void displayClear()
{
        digitalWrite(3,HIGH);
        digitalWrite(4,HIGH);
        digitalWrite(5,HIGH);
        digitalWrite(6,HIGH);
        digitalWrite(7,HIGH);
        digitalWrite(8,HIGH);
        digitalWrite(9,HIGH);
}

void displayNumber(int LedNumber)
{

    switch(LedNumber)
    {
      case 1 :
        digitalWrite(4,HIGH);
        digitalWrite(7,HIGH);
        break; 
      
      case 2 :
        digitalWrite(3,HIGH);
        digitalWrite(4,HIGH);
        digitalWrite(5,HIGH);
        digitalWrite(9,HIGH);
        digitalWrite(8,HIGH);
        break;
      case 3 :
        digitalWrite(3,HIGH);
        digitalWrite(4,HIGH);
        digitalWrite(5,HIGH);
        digitalWrite(7,HIGH);
        digitalWrite(8,HIGH);
        break;
      case 4 :
        digitalWrite(6,HIGH);
        digitalWrite(5,HIGH);
        digitalWrite(4,HIGH);
        digitalWrite(7,HIGH);
        break;
      defult :
        digitalWrite(5,HIGH);
        break;
    }
}

//返回参数的值，int是返回参数的数据类型

int GetNumber(int min, int max)
{
  int randomNumber;
  randomNumber =random(min,max);
  return randomNumber ; 
}