PCF 8574 example from nopnop

[Turnoff]

Hello sir
Thank you so much for your help!
In your topic PCF8574 you give as an example a link to a Japanese author “nopnop”.
It’s very interesting, but I’m a novice, and I don’t understand the meaning of this line of code:
Could you explain to me the meaning of the two ::?

PCF8574 :: DigitalInput val = pcf8574.digitalReadAll ();

Slowly please 🙂 like a child
I’m just starting out, and it’s been fifteen days that I browse the websites, and in fact I’m going from one problem to another. the syntax of C is difficult.
Thank you anyway and long life to your blog

[Renzo Mischianti]

Hi Turnoff,
you can understand the syntax when you check the structure of the PCF8574 class:

class PCF8574 {
[...]
		struct DigitalInput {
			uint8_t p0;
			uint8_t p1;
			uint8_t p2;
			uint8_t p3;
			uint8_t p4;
			uint8_t p5;
			uint8_t p6;
			uint8_t p7;
		} digitalInput;
[...]
}

there is a structure DigitalInput declared inside the PCF8574 class declaration, so to reference the Object inside It you must use :: notation.

PCF8574::DigitalInput

I hope I was clear.

Bye Renzo

[Turnoff]

Thank you for answering so quickly
Okay, that’s how it is …
It is beyond me a bit but if it is a rule of writing. I will apply it
Sorry for posting 2 times 🙁
have a good day

[Renzo Mischianti]

Don’t worry Turnoff,
for every doubt or qwestion write a topic without problems.
Bye Renzo

[Author]

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