arduino：循环直到int获得值分配给它

Question

I am trying to get a value from serial input. The rest of the programm behaves different if the value changes. This value gest assigned once in the ```void setup()``` function.
My goal is to let the program run an infinite loop or something similar until a value (type int) is recived, and only then resume the flow.
I know about ```Serial.parseInt()``` and tried to implement it ``` while (variable == null) variable = Serial.parseInt() ``` but I got an error that 'null' was not declared in this scope.
Any suggestions?

Answer 1

Oke，我有点愚蠢。
有一种简单的方法，只需检查一下

while (!variable) 
  variable = Serial.parseInt()

这对我有用，也应该为您工作