I have the following constructor and need to push the constructor object into a vector. How do I do so? My current method doesn't seem to work.
`
class A : public B(...)
{
vector<A> numObj;
A(int a){
numObj.push_back(A(3));
}
}
#referencing object created in constructor c++?
sweet sparrow
elder portal
you do know that variable is an instance variable, right?
which means that each instance of class A will have its own numObj variable
sweet sparrow
which means that each instance of class `A` will have its own `numObj` variable
I moved numObj to my A.h header file and made it extern. However, when I run my main.exe, none of my print statements output anymore
elder portal
show code
sweet sparrow
A.h:
`
#pragma once
class A: public B{
A(int a);
}
extern vector<A> numObj
A.cpp:
vector<A> numObj;
A::A(int b): B(b){
numObj.push(back(A(b));
}
`
elder portal
it would probably be better to just do numObj.push_back(*this);
does your program ever halt?
sweet sparrow
does your program ever halt?
yes, whenever I run my .exe file, nothing is printed out
when before I added this class, the print statements worked just fine
elder portal
by halting i meant terminate
im asking because your constructor calls itself, so it's an infinite loop
sweet sparrow
#include "<A.h>" int main(){ cout << "test"'; A test(3); cout << "test 2"; }
"test" is printed but not "test 2"
elder portal
by halting i meant terminate
answer me this
sweet sparrow
answer me this
yes the code does terminate
elder portal
you can do code block with triple backticks btw
sweet sparrow
Oh
elder portal
yes the code does terminate
that doesn't make sense
elder portal
im asking because your constructor calls itself, so it's an infinite loop
because of this
sweet sparrow
Ill show my B.cpp code maybe thats the issue
elder portal
it absolutely isn't
sweet sparrow
B.cpp:
#include "A.h"
vector<A> numObj;
B(int b){
numObj.push_back(A(b));
}
well, unless the constructor for B exits your program
same thing
the infinite loop is still there
A() calls B() which calls A() which calls B()......
sweet sparrow
my code seems to work when I comment out numObj.push_back(A(b)); "test 2" is printed out
elder portal
what platform are you on?
sweet sparrow
Windows
elder portal
it's impossible that your program is terminating
is there an error message?
like out of memory?
idk
sweet sparrow
no nothing
sweet sparrow
no
elder portal
idk how they work on windows
sweet sparrow
is there a better way to insert the constructor object into the vector then?
elder portal
on linux you cant just echo $? to get the error code of the previous command
elder portal
and i remove that line from B's constructor as well
sweet sparrow
and i remove that line from B's constructor as well
yea removing that line made it work
elder portal
yeah, that's the best approach
sweet sparrow
but if i wanted to push back the A object from B's constructor is there a good way
to do so?
should I just do A::A(int a):B(*this){...}?
elder portal
maybe
although idk why you'd want to do this
and if B is supposed to be a super class it shouldn't be aware of A's existence
this is a general rule, ofc
sweet sparrow
The B class's vector is supposed to contain all the subclasses objects
so I call it everytime I create a new object for any class
elder portal
i can't help any further for now
but i'd advice you to rethink what exactly you're trying to achieve
because this seems somewhat counterintuitive (and even dangerous)
sweet sparrow
thank you for all the help, im very thankful