Can we initialize data members in a class in C++?

Can we initialize data members in a class in C++?

In C++, class variables are initialized in the same order as they appear in the class declaration. The program prints correct value of x, but some garbage value for y, because y is initialized before x as it appears before in the class declaration. …

Why can’t we initialize members inside a structure?

The direct answer is because the structure definition declares a type and not a variable that can be initialized. Your example is: struct s { int i=10; }; This does not declare any variable – it defines a type.

Why don’t we initialize the static data member in the constructor of the class?

1) Static variables are property of the class and not the object. 2) Any static variable is initialized before any objects is created. That’s why compiler don’t allow to define static variable inside constructor as constructor will be called when a object is created.

Can we initialize data members in class?

In Java, you can initialize a variable if it is a member of the class. There are four ways to initialize members of the class data: initialization by default (implicit initialization); explicit initialization with initial values (constant values);

How do you initialize a class member?

To initialize a class member variable, put the initialization code in a static initialization block, as the following section shows. To initialize an instance member variable, put the initialization code in a constructor.

How do you check if a variable has been initialized C++?

There is no way in the C++ language to check whether a variable is initialized or not (although class types with constructors will be initialized automatically). Instead, what you need to do is provide constructor(s) that initialize your class to a valid state.

Can we declare structure inside structure * 1 point a yes b no?

No, you cannot define a function inside the structure of C Programming, but you can do so in C++, rather you can have a function pointer in a “struct” in C Language.

Can we initialise inside a structure?

Structure members cannot be initialized with declaration. For example the following C program fails in compilation. The reason for above error is simple, when a datatype is declared, no memory is allocated for it.

Can a constructor be overloaded?

Yes! Java supports constructor overloading. In constructor loading, we create multiple constructors with the same name but with different parameters types or with different no of parameters.

What happens if a user forgets to define a constructor inside a class?

What happens if a user forgets to define a constructor inside a class? Explanation: The C++ compiler always provides a default constructor if one forgets to define a constructor inside a class.

Can we initialize private members in a class C++?

Here we will see how to initialize the private static member variables initialization in C++. We can put static members (Functions or Variables) in C++ classes. To initialize we have to use the class name then scope resolution operator (::), then the variable name. Now we can assign some value.

Which is the method to initialize data members of a class?

constructor
Initializing Instance Members There are two alternatives to using a constructor to initialize instance variables: initializer blocks and final methods. The Java compiler copies initializer blocks into every constructor. Therefore, this approach can be used to share a block of code between multiple constructors.

When do we initialize a member of a class?

If you have a data member such as int x;, no int object is created until you actually create an object of the type of the class. Therefore, an initializer on this member would be misleading. It is only during construction that a value can be assigned to the member, which is precisely what member initialization lists are for.

Can a static data member be initialized more than once?

A static data member is shared among all instances of the class. It can be initialized once (by definition of initialization), so it wouldn’t make sense to initialize it for each instance. You could, however, assign it a value (or mutate the existing value) in the constructor body.

Why does C + + 11 not initialize class members?

If you compile with a C++11 compiler, it should happily accept the code you have given. I imagine that the reason for not allowing it in the first place is because a data member declaration is not a definition. There is no object being introduced.

Why is static data not initialized in ctor?

If you initialize in ctor then it means that you are trying to associate with a particular instance of class. Since this is not possible, it is not allowed. I presume you’re referring to using it in an initialization list to a constructor. A static data member is shared among all instances of the class.