hi, i defined this function in my class: inline std::vector<Point> Curve::vector() const { return m_points; } is it possible to return a reference to m_points? i tried doing: inline std::vector<Point>& Curve::vector() const { return &m_points; } but i get 'initial value of reference to non-const must be an lvalue' error

What is m_points? Is it a member of class Curve or a local variable inside Curve::vector method?

it's a vector, a member variable of class Curve

It is not a good idea to return a reference to member variable. Your function is a const member function. It means that it doesn't change the data members of the class (unless they are mutable). So if you must definitely return a reference, then a const member function has to return a const reference only. It can't return a non const reference because the implicit this pointer is a pointer to a const. If you change your return value to a const reference, then all that you have to do is just remove the & before m_points in the return statement. A reference is not the same as a pointer.

> It is not a good idea to return a reference to member variable. valid, but how do i make a getter for a vector? const reference? or copying is the only choice thanks for the other points too :D

If you have a vector as a member variable and want to give users read only access to it directly, here are your options: 1) you can return a const reference to it 2) return a copy. 3) you can just return a pair of const iterators to the vector with the caveat that the iterators can be invalidated. (With C++ 20, you can return a range instead) But before you do any of the above, think whether you want the users of your class to be exposed to your class's implementation details. If tomorrow you decide that a vector is not the way to go about and switch to use a coroutine that generates values on the fly instead, then all of your return values will be useless. This would mean any such change would impact your users So you would instead have to think what meaningful things would the client be able to do with the vector if you return it to them. If you know what they are going to do,then you should provide those options as part of your interface.

so, the function signature should look something like this? inline const std::vector<Point>& Curve::vector() const {

That's right, the only problem on the code above was the & before m_points so instead of: return &m_points; use: return m_points;

yep, did that

When I call a function like this Int main (){ //call Function of int jump here }; Void Int jump(){ }; The code don’t run in visual studio But when I do it like this it run .. Void Int jump(){ }; Int main (){ //call Function of int jump here }; Why?

Can anyone help me with a c program

what's the question/problem? what do you need help with?

no

..you just insert it after the lines where you write the maximum and printf the minimum

Max output isn't being shown

D:\>gcc bruh.c D:\>a.exe Enter quantity of 1st 2nd and 3rd item : 8 6 3 Enter price of 1st 2nd and 3rd item: 2.0 3 77 . 231 is maximum revenue 16 is minimum revenue i had to put enter another character and press enter so that the output would be shown

Solved ?

Its showing err

Ig it's the compiler err

Message ?

That's not compile error

Then

How can I fix it

Yeah ig

Do you compile in right directory ?

why the answer is some garbage value when I am taking value at run-time ? #include <bits/stdc++.h> using namespace std; int main(){ int n1; cin>>n1; int limit=sqrt(n1); // returning some garbage value cout<<limit; return 0; }

cout << setprecision(12) << 0.123f; output: 0.123000003397 Where in the world setprecision gets last 4 digits from if float is not so precise?

because thats how float or double are stored in pc try read ieee 754 for more detail. some nice link. https://www.exploringbinary.com/floating-point-converter/

I've remembered, thx.