What is default value of member variable C++?

What is default value of member variable C++?

Unlike some programming languages, C/C++ does not initialize most variables to a given value (such as zero) automatically. Thus when a variable is assigned a memory location by the compiler, the default value of that variable is whatever (garbage) value happens to already be in that memory location!

Are class members zero initialized?

If T is an non-union class type, all base classes and non-static data members are zero-initialized, and all padding is initialized to zero bits. The constructors, if any, are ignored.

Are class members default initialized C++?

every element of aa1 and aa2 are default initialized. every element of av1 and av2 are value initialized.

What is default initialisation?

Default initialization is performed in three situations: 1) when a variable with automatic, static, or thread-local storage duration is declared with no initializer; 3) when a base class or a non-static data member is not mentioned in a constructor initializer list and that constructor is called.

Does C++ initialize member variables?

To solve this problem, C++ provides a method for initializing class member variables (rather than assigning values to them after they are created) via a member initializer list (often called a “member initialization list”). The member initializer list is inserted after the constructor parameters.

How can we provide a default value for a member of a class?

You can simply provide a default value by writing an initializer after its declaration in the class definition. Both braced and equal initializers are allowed – they are therefore calle brace-or-equal-initializer by the C++ standard: class X { int i = 4; int j {5}; };

Does C++ zero initialize?

Zero Initialization in C++ Setting the initial value of an object to zero is called the zero initialization. Zero is initialized for every named variable with static or thread-local storage duration that is not subject to constant initialization (since C++14), before any other initialization.

How do I change the default value of a class in C++?

What is the default initial value of a string in C++?

null
Strings. Variables of type “String” are treated as Objects in this case and have a default value of null.

How do you initialize a class member in C++?

There are two ways to initialize a class object:

1. Using a parenthesized expression list. The compiler calls the constructor of the class using this list as the constructor’s argument list.
2. Using a single initialization value and the = operator.

How do you initialize values of data members of a class in C++?

To initialize the const value using constructor, we have to use the initialize list. This initializer list is used to initialize the data member of a class. The list of members, that will be initialized, will be present after the constructor after colon. members will be separated using comma.

What is the default value of string in C++?