A basic C++ question

[QQ]

Hello, I am new on C++, I am reading one source code
ZThread::ZThread(char *threadname):bug("ZThread")
~~~~~~~~~~~~~~~~~~~What does it mean?

Thanks a lot!

{
........
}

 

[Victor Bazarov]

Hello, I am new on C++, I am reading one source code
ZThread::ZThread(char *threadname):bug("ZThread")
~~~~~~~~~~~~~~~~~~~What does it mean?

Thanks a lot!

{
.......
}

It's called "initialiser list" ("initializer list"). The member
named 'bug' is initialised with a const char[] argument (a string
literal).

V

 

[Rolf Magnus]

Hello, I am new on C++, I am reading one source code
ZThread::ZThread(char *threadname):bug("ZThread")
~~~~~~~~~~~~~~~~~~~What does it mean?

Which C++ book are you reading that doesn't explain initializer lists? This
is a very basic concept of C++.
The above means that 'bug' is either the name of a base class of ZThread or
the name of one of its data members. In the former case, the base part of
your object is initialized using its constructor that takes a const char*.
In the latter, the data member is initialized with such a constructor.
Without the initializer, the default constructor would be used.

 

[eKIK]

It means you've got a method called ZThread in a class called ZThread
(constructor) which take a char pointer as argument and sets the value
of the variable bug to "ZThread".

ZThread::ZThread(char* threadname)
{
bug = "ZThread";
}

This is just another way of writing the (nearly) exact same thing.

Hope this helps!
// eKIK

 

[John Dibling]

That looks like a constructor initialization list.

</dib>

 

[Lionel B]

It means you've got a method called ZThread in a class called ZThread
(constructor) which take a char pointer as argument and sets the value
of the variable bug to "ZThread".

not "sets the value"; *initialises* bug with ZThread

ZThread::ZThread(char* threadname)
{
bug = "ZThread";
}

This is just another way of writing the (nearly) exact same thing.

Terrible advice... not even "nearly":

1) If bug is declared const it won't compile.

2) If bug is an instance of a class with a constructor taking parameter char* it either won't compile (if bug's class
lacks an assignment operator for char*) or otherwise may not do what you expect it to, since bug's char* constructor
won't be called.