System.String is a class. However, it is somewhat unique in that it is immutable, meaning that it is readonly. So if you change the contents of a string, Behind the Scenes it creates a new string object and destroys the old one.
The keyword class is not a keyword in C. It is a keyword in C++, so I have added C++ to the category list for this question.The default access specifier for struct is public, while for class, it is private.Struct does not allow you to specify methods, while class does.A struct is not a class, and cannot be derived, while a class can be treated as a struct, if the scope and access is correct.
The struct type is suitable for representing lightweight objects such as Point, Rectangle, and Color. Although it is possible to represent a point as a class, a struct is more efficient in some scenarios. For example, if you declare an array of 1000 Point objects, you will allocate additional memory for referencing each object. In this case, the struct is less expensive. When we create a struct object using the new operator, it gets created and the appropriate constructor is called. Unlike classes, structs can be instantiated without using the new operator. If you do not use new, the fields will remain unassigned and the object cannot be used until all of the fields are initialized. It is an error to declare a default (parameterless) constructor for a struct. A default constructor is always provided to initialize the struct members to their default values. It is an error to initialize an instance field in a struct. There is no inheritance for structs as there is for classes. A struct cannot inherit from another struct or class, and it cannot be the base of a class. Structs, however, inherit from the base class Object. A struct can implement interfaces, and it does that exactly as classes do. A struct is a value type, while a class is a reference type.
Nested structures means we can have a structure inside another eg: struct A { ........... ............ struct B { ........ ........ }b; }a;
A struct in C is a POD (plain old data) type. A class in C++ can also be a POD for backward compatibility with C code, but more typically combines data with methods that operate upon the data, including constructors and initialisers. Classes in C++ can be declared using either the struct or class keyword. By convention you will typically use struct to define POD data types and class to define more complex data types. The only practical difference between a struct and a class is that classes use private access and inheritance by default while struct uses public access and inheritance by default. Thus the following two class definitions are functionally the same: struct A { A():m_data(0) {} // public access by default private: int m_data; }; class B { int m_data; // private access by default public: B():m_data(0) {} };
A C struct only has public member variables whereas a C++ class combines member variables with member functions; the methods that operate upon the data. Moreover, each member of a class can be assigned a different level of access from public, protected or private access, thus limiting the member's exposure. This allows classes to hide data and implementation details from outside of the class, exposing only as much as is necessary in order to use the class. Thus the class becomes entirely responsible for the integrity of its data, while its methods act as the gatekeepers to that data.Note that in C++, a struct is exactly the same as a class, other than the fact that the members of a struct are public by default while members of a class are private by default, unless explicitly declared otherwise. Aside from that they operate in exactly the same way. In other words, a C++ struct is not the same as a C struct.
The keyword class is not a keyword in C. It is a keyword in C++, so I have added C++ to the category list for this question.The default access specifier for struct is public, while for class, it is private.Struct does not allow you to specify methods, while class does.A struct is not a class, and cannot be derived, while a class can be treated as a struct, if the scope and access is correct.
struct A {}; // base class struct B : A {} // derived class (single inheritance).
You don't need a typedef to declare a struct in C++. A struct is declared exactly the same way that you would declare a class, the only difference being that struct members are public by default, while class members are private by default. Aside from that the class and struct keywords are completely interchangeable.
The default access specifier for a class is private. The default access specifier for a struct is public. It does not matter if it is a function or a variable.
The struct type is suitable for representing lightweight objects such as Point, Rectangle, and Color. Although it is possible to represent a point as a class, a struct is more efficient in some scenarios. For example, if you declare an array of 1000 Point objects, you will allocate additional memory for referencing each object. In this case, the struct is less expensive. When we create a struct object using the new operator, it gets created and the appropriate constructor is called. Unlike classes, structs can be instantiated without using the new operator. If you do not use new, the fields will remain unassigned and the object cannot be used until all of the fields are initialized. It is an error to declare a default (parameterless) constructor for a struct. A default constructor is always provided to initialize the struct members to their default values. It is an error to initialize an instance field in a struct. There is no inheritance for structs as there is for classes. A struct cannot inherit from another struct or class, and it cannot be the base of a class. Structs, however, inherit from the base class Object. A struct can implement interfaces, and it does that exactly as classes do. A struct is a value type, while a class is a reference type.
Class only exists in C++. The struct more closely resembles class but with less features.
In C#, a struct is a Value type derived from Object, and provides no inheritance.A class is also derived from Object but as a Referencetype, also allow subtypes to be drived from a class, unless it is declared as sealed.That is, a struct like:public struct A {}anda class like:public sealed class B {}Are almost the same, except when an instance being passed as an argument to a method, an instance of A is passed by value, while an instance of B is passed by reference (by default).A class can be declared as abstract, while a struct cannot be one.class provides a class hierarchy (yes you can build a class tree), while struct is a flat and boring 1-level sealed module unit (but as a value type).
Nested structures means we can have a structure inside another eg: struct A { ........... ............ struct B { ........ ........ }b; }a;
The only difference between a struct and a class in C++ is that struct members are public by default while class members are private by default. Other than that they act and behave in exactly the same way and are both used to define classes. By convention, struct is used exactly as it would be used in C, with all public members and no member functions, to provide backward compatibility with C-style code.
A struct in C is a POD (plain old data) type. A class in C++ can also be a POD for backward compatibility with C code, but more typically combines data with methods that operate upon the data, including constructors and initialisers. Classes in C++ can be declared using either the struct or class keyword. By convention you will typically use struct to define POD data types and class to define more complex data types. The only practical difference between a struct and a class is that classes use private access and inheritance by default while struct uses public access and inheritance by default. Thus the following two class definitions are functionally the same: struct A { A():m_data(0) {} // public access by default private: int m_data; }; class B { int m_data; // private access by default public: B():m_data(0) {} };
Yes. The only difference between a struct and a class is that a struct's members and inheritance is public by default, while a class' members and inheritance are private by default. Structs can derive from classes and classes can derive from structs. As such, they are polymorphic.
structure variable can access the variable but class object can access the function also