How to define static members in a static function in .cpp file?

[thippu]

@jsulm said in How to define static members in a static function in .cpp file?:

double AmpConfiguration::sampling_rate;

double AmpConfiguration::sampling_rate=10.2 //like this? in the static function?

[jsulm]

@thippu said in How to define static members in a static function in .cpp file?:

in the static function?

No. Like this:

double AmpConfiguration::sampling_rate=10.2;
void AmpConfiguration::ReadIni()

See https://en.cppreference.com/w/cpp/language/static

[thippu]

@jsulm yes bro, I did add like this double AmpConfiguration::sampling_rate=line_list->at(0).toDouble();
but new error came qualified-id decalration before "=" token

[jsulm]

@thippu said in How to define static members in a static function in .cpp file?:

double AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

Please read again what I wrote.
Where do you call this now?
It looks like you're now trying to declare a LOCAL variable with same name which is for sure not what you want to do.

[thippu]

@jsulm said in How to define static members in a static function in .cpp file?:

Where do you call this now?

In the mainwindow.cpp

[jsulm]

@thippu said in How to define static members in a static function in .cpp file?:

In the mainwindow.cpp

WHERE EXACTLY?

[thippu]

@jsulm
In the constructor of mainwindow.cpp
I'm calling AmpConfiguration::ReadIni(); First statement itself

[jsulm]

@thippu Can you actually be more precise when answering questions?
Do you mean you put that line in the constructor or inside ReadIni()?
But as I said: you're declaring a local variable with same name.
It must be like this:

AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

AmpConfiguration:: can be removed as well...

[thippu]

@jsulm said in How to define static members in a static function in .cpp file?:

local variable

I would like it to be a global static variable.

and I would like to use it(initialize) inside AmpConfiguration::ReadIni()

@jsulm said in How to define static members in a static function in .cpp file?:

AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

finally, Calling the AmpConfiguration::ReadIni()in constructor of mainwindow.cpp.

[thippu]

@jsulm said in How to define static members in a static function in .cpp file?:

AmpConfiguration::sampling_rate=line_list->at(0).toDouble();

No, change in the error. still, I'm getting undefined reference

[jsulm]

@thippu "I would like it to be a global static variable." - then why do you declare it as local variable?
Did you put

double AmpConfiguration::sampling_rate=10.2; // This has to be OUTSIDE of any method/constructor
void AmpConfiguration::ReadIni()
{
    sampling_rate=line_list->at(0).toDouble();
}

as I already wrote above?
Please read about static members in C++.

[thippu]

@jsulm said in How to define static members in a static function in .cpp file?:

// This has to be OUTSIDE of any method/constructor

Worked. bro
Thank you