Probably an embarrassingly simple question -- but I'm more interested in knowledge than pride.

Probably an embarrassingly simple question – but I’m more interested in knowledge than pride. :slight_smile:

Typically, when calling functions in a void loop, I see the following format…

void loop()
{
marqueeWhite();
}

But on occasion, I’ve seen a value in the parentheses, like so…

void loop()
{
marqueeWhite(30);
}

Can someone tell me what that number does?

Thanks!

Not sure what the marqueeWhite() method does, but the number seems to be an optional parameter.

example:

void setBrightness(int t=100){
 // do something
}

if you now call
setBrightness()
it would be the exact same call as if you would call
setBrightness(100)
And should set the brightness to 100%.
The call
setBrightness(30)
should set the Brightness to 30%

So what is actually happening with the number is defined in the method itself. If you see it in the source code, you will see what the default value is.

@allanGEE It can be quite useful once you understand this. :slight_smile:

https://www.arduino.cc/en/Reference/FunctionDeclaration

@marmil Great… now a bunch of interesting stuff that I should NOT read while at work! :wink: Thanks for the links!

@allanGEE unless your work is Arduino programming, then you probably should :wink: