#include 
Using namespace STD. 
Class a 
{
Public: 
int x; 
A (int I=10) 
{
X=I; 
cout<& lt;" A: "& lt; } 
}; 
Class b: public a 
{
A, a. 
int x; 
Public: 
B (int I) : (I) 
{
X=I; 
cout<& lt;" B: "& lt; } 
}; 
Int main () 
{
B b (5); 
return 0; 
} 

A: I want to know this: why is 10 x

CodePudding user response:

To understand what is a: : x

CodePudding user response:

Default parameters, you did not show the superclass constructor calls B, but the compiler invocation, the inherited from the parent class B members are initialized to 10;

CodePudding user response:

A: : x spelled wrong grammar, you find a standard compiler try will know,
I know vc6 support this kind of writing, but he is wrong grammar, x is the static variables can be used to this kind of writing,

CodePudding user response:

Because you are in a class b extra defines int x; Although the same name with its parent class member variables, but not the same, and because of the same name, x will be hidden in a, need to specially designated to access to a of x

CodePudding user response:

A class has a x, you why again to define a class b x. no one will be done in actual development

CodePudding user response:

CodePudding user response:

Many idea is wrong, upstairs,
1, the reason of your problems I've said above the
2, your grammar is no mistake, it is you have a problem naming conventions, classes generally begin with a capital letter, instances of the class will typically use a lowercase letter, you are totally opposite

CodePudding user response:

I wrong, that is a member function, me as an ordinary function

CodePudding user response:

I write this is reading programs on the Internet looking for the results of the title, format might be a little problem, but run there is no question that is not covered by the parameter name repetition, in another post, I found the answer, you are interested can go to the next: https://bbs.csdn.net/topics/396410092
In general is an A (I) is the answer, I want A (I) without this, it would be 10

B (int I) : (I), A (I)//-- -- -- -- -- -- -- -- explicitly call A constructor, at this point A is no longer the default constructor argument, but I -- -- -- -- -- -- -- -- -- -- -- --
{
X2=I;
//A: at this time: the value of x is 5
Cout & lt; <"B:" & lt; }

CodePudding user response:

the pearl of reference to the tenth floor I have a reply:

I write this is reading programs on the Internet looking for the results of the title, format might be a little problem, but run there is no question that is not covered by the parameter name repetition problems, I found the answer in another thread, we are interested can go to the next: https://bbs.csdn.net/topics/396410092
In general is an A (I) is the answer, I want A (I) without this, it would be 10

B (int I) : (I), A (I)//-- -- -- -- -- -- -- -- explicitly call A constructor, at this point A is no longer the default constructor argument, but I -- -- -- -- -- -- -- -- -- -- -- --
{
X2=I;
//A: at this time: the value of x is 5
Cout & lt; <"B:" & lt; }

You still didn't understand,,,
The floor back to your post posted friends should know what you said the other,,,

CodePudding user response:

I be a small white, deep I also don't understand, tell me where the code change is ok, I can read it