Document ternary operator

[thedub2001]

Hello I just discovered the the Serial.print() function can be used with conditional testing :

Serial.print(test ? "test=true" : "test=false");

If the "test" variable is true then the output will be :

test=true

If the "test" variable is false then the output will be :

test=false

I just thought this function could appear somewhere in the Serial.print() reference documentation

[facchinm]

Well, it's not only about Serial.print , the ternary operator is allowed in any function if the "arguments" type is correct. However, it could be surely documented, but I'd prefer waiting until we merge some of these PRs

[NeatNit]

I think the ? : operator is a common enough source of confusion to warrant a mention in the reference. I think it would fit nicely under "Further Syntax":

[juanpablojofre]

I'm with @NeatNit!!
The ternary operator should be documented as part of the syntax of the language.
Where I disagree with @NeatNit is in the location.
Since it's an operator, it should be listed as such.
I would suggest a new header: Conditional Operator
and the entry underneath as:

• ? : (ternary operator)

[NeatNit]

It would be lonely all by itself under that header. 😢

[cousteaulecommandant]

Definitely not under "Further syntax"; this is just a plain old operator. Maybe under "Boolean operators".

[feikname]

Why not under control structures? The ternary operator is esssentially a one-line alternative to if {} else { } blocks.

[cousteaulecommandant]

Why not under control structures?

I'd rather not, since it's quite different from a control structure in how it's used – the statements in that section are typically used with blocks of code, which doesn't work with ? :.
However it might be possible to put the documentation of ? : as a section of the documentation for if as is done with comparison operators (and if not, I'd definitely link to ? : on the "See also" section of if).

[thedub2001]

I found another strange operator and I can't find documentation, perhaps it could be gathered at the same place in future documentation :

for (auto dataobj : data){
    Serial.println(dataobj.key);
}

example from https://bblanchon.github.io/ArduinoJson/doc/decoding/

[feikname]

@thedub2001 It's a range-based for loop.

[cousteaulecommandant]

for (auto dataobj : data)

I'd classify that as "advanced C++ 'black magic' that is out of the scope of the Arduino documentation".
In fact all the code in that page uses quite a lot of C++ mechanisms such as references, templates, and custom classes with operator overloading, which also exist in the internal Arduino code but are usually opaque to the user.

[per1234]

Moved to arduino/reference-en#519