kotlin constructors

The most basic function of a constructor is to assign an initial value to all the fields and properties in a new instance of the type. So, according to its function, he doesn't need (and doesn't make sense) the return value. His function name must be the same as the class name.Constructors for reference typesWhenever you create an instance of a class or struct, you call its constructor. A class or struct may have multiple constructors that accept diff

The constructor is a member function that initializes an instance of its class. The constructor has the same name as the class and does not have a return value. A constructor can have any number of arguments, and a class can have any number of overloaded constructors. Constructors can have any accessibility (public, protected, or private). If no constructors are

Objective This article summarizes the copy constructors and overloaded assignment operators in C + +, including the following: 1. Copy the constructor and the definition of the overloaded assignment operator;2. The timing of the invocation of the copy constructor and the overloaded assignment operator;3. Replication constructors and overloaded assignment operators to achieve the main points;4. Copy some d

This series of articles is a personal reading note and summary content, any organization or individual may not be reproduced for commercial activities. Nineth Chapter: Constructors and garbage collectors-objects of previous life The object of Life and death:You must be responsible for the life cycle of the object, when to create, when to destroy (not eliminate, just give up), evaporate it by the garbage collector (GC), and reclaim the space it occup

Transfer from http://blog.csdn.net/tqtuuuu/article/details/6652144constructor functionFor C + + constructors, it is divided into the following categories: 1. Default constructors 2. Hermit conversion constructor 3. Copy Constructors 4. Other constructors 1. The default constructor represents a

Construction operation of Default constructorFor class X, if there is no user-declared constructor, then a default constructor is declared implicitly (implicit), an implicitly declared default Constructor will be a trivial consructor ...The following is a discussion of the 4 cases of nontrivial default constructor.　1. member Class Object with default constructorIf a class does not have any constructor, but it contains a member object, and the latter has the default constructor, then the class im

constructors, destructors constructor function: 1. If no constructor is provided, the system automatically provides a default constructor that initializes all members as default values (reference type is null reference NULL, value type is 0,bool type is false); 2. If a constructor with a parameter is provided, the system does not provide a default constructor function; 3. Constructors can be overloaded:

Inadvertently see an article on the base class and subclass constructors problem, from: http://blog.sina.com.cn/s/blog_64d57e710100n24f.htmlThis will cause an error:But run:The result will still be output:This obviously means that although a space is created for a, member functions are constructed, but the data of a is not initialized, and A's data is a random number to read.Why?In another case, if you add a default constructor to Class A and then use

Constructors and destructors are two special member functions of a class 1. Constructors A constructor (constructor) is a special member function of a class that has the same name as the class name. When an object of this class is defined, the constructor is automatically invoked by the system to implement initialization of the object. Constructors cannot have

Constructors and destructors are two types of functions that seem to be simpler in a class, but there are always some unexpected errors in the actual application process. This paper will introduce the principle of constructor function and destructor and the application in C #, and some matters needing attention in the process of using. A The principle of constructors and destructors As a more advanced lan

FAQQ1. what is the output of the following code? 1#include 2 using namespacestd;3 4 classA5 {6 Public: 7A () {cout "A"Endl;}8~a () {cout "~a"Endl;}9 }; Ten classD | PublicA One { A Public: -B (a a): _a (a) {cout "B"Endl;} -~b () {cout "~b"Endl;} the Private: - A _a; - }; - + intMainintargcChar*argv[]) - { + A; A b b (a); at return 0; -}Q2. The result of the output after test execution is ()1 voidTest ()2 {3 classB4 {5 Public:6B () {cout "b\t"; }7~b () {cout "~b\t"; }8

SkillsMost of the content in this book is a programming guideline. Although these guidelines are important, programmers cannot live by the rules alone. There is a long-time cartoon called "Philip Cat" (Felix the Cat), Philip Cat whenever encountered difficulties, it will take its trick bag. If a cartoon character has a trick package, then C + + programmers should have more. Think of this chapter as the starter of your trick bag.When designing C + + software, there are always some problems to be

Objective: First we need to know why we want to use constructors, or we need to know what we can do with constructors to solve our problems:1, when assigning the initial value, we may need to repeat the object name, but if the use of the constructor is not so cumbersome. After all, the code is like that, the shorter the better (as everyone knows, I won't say it).2, if there is such a property, do not allow

PHP Magic Methods-constructors and destructors, PHP magic Constructors PHP has a kind of magic method, these methods are reserved methods, usually not explicitly called outside, they use double underscore (__), they are called Magic Methods. PHP is also not recommended to define a method that starts with a double underscore. This introduction is the most common magic method:

Constructors and destructors are fixed in PHP, as follows://constructor function __construct ([Argument1,argument2,...,Argumentn]) {/ * Class Initialization code */ }//destructor function __destruct () { //...}constructor Function Constructors can accept parameters and be able to assign values to object properties when creating an object Constructor