Simplify the code like this:

 
Class A 
{
Public: 
Int length (); 
} 
Class B 
{
Private: 
A * A; 
Public: 
A * getA () {return A}; 
} 
Int main () 
{
B B; 
EtA (int len=b.g.) length (); 
} 

Results the destructor is called my b content changed, want to along while didn't want to see,, save the children!!!!!!!!!

CodePudding user response:

It doesn't run wrong? B.g etA () returns null pointer, or do you omitted to b.a initialization code?

CodePudding user response:

GetA () returns a is not initialized
For the uninitialized pointer, calls its methods is bound to go wrong

CodePudding user response:

I have a problem, simplify the source these are initialized, and then I modify and add a function in a class B

 
Void getLength () 
{
Return a - & gt; The length (); 
} 

Good, but I don't know the specific reason,

CodePudding user response:

 # include 
Class A 
{
Public: 
Int length=9; 
}; 
Class B 
{
Private: 
A * A; 
Public: 
(B) 
{
A=new a; 
} 
A * getA () {return A; } 
}; 
Int main () 
{
B B; 
Int len=b.g etA () - & gt; Length; 
Len: printf (" % d \ n ", len); 
return 0; 
} 

Len: 9

Process finished with exit code 0

CodePudding user response:

reference 4 floor studyyyyyyyyyy response:

I have a problem, simplify the source these are initialized, then I changed, added a function in a class B

 
Void getLength () 
{
Return a - & gt; The length (); 
} 

Good, but I don't know the specific reason,

Members of the pointer call them use - & gt;

CodePudding user response:

Write the wrong but my length is a member function
My problem is to use the bidirectional circular linked list implementation of arbitrary length integer addition and subtraction, and then my class is A linked list class, class B is integer, then the getA () is to get the head node, length () is the length of the access to the list, when I wrote the int len=b.g etA () - & gt; The length (); My the b list inside a destructor didn't (empty lists), don't know why, the return value is the return a; Local variables are the destructor?
For the first time in this BBS, always write wrong, sorry!

CodePudding user response:

Also did not see you the destructor

CodePudding user response:

Must be new, simplified is wrong, you write in the constructor