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Total of 270 Constructor Solutions
How does Python's "super" do the right thing?
Python
Constructor
Multiple Inheritance
Super
Python 2.5
Is there any reason to choose __new__ over __init__ when defining a metaclass?
Python
Constructor
New Operator
Metaclass
Init
How to chain method on a newly created object?
Php
Constructor
New Operator
Method Chaining
Closing a form during a constructor
C#
Winforms
Constructor
Is generic constructor in non-generic class supported?
C#
Generics
Constructor
Why use an initialization method instead of a constructor?
C++
Constructor
Initialization
Can I call methods in constructor in Java?
Java
Constructor
Why doesn't Java have initializer lists like in C++?
Java
C++
Constructor
Initialization
Initialization List
In Ruby, what's the relationship between 'new' and 'initialize'? How to return nil while initializing?
Ruby
Constructor
Return
New Operator
Initializer
C++ - initializing variables in header vs with constructor
C++
Constructor
Initialization
How many constructors does the class have?
C++
Oop
Constructor
Static factory methods vs Instance (normal) constructors?
Design Patterns
Constructor
Coding Style
Purpose of PHP constructors
Php
Class
Oop
Constructor
Base Class Doesn't Contain Parameterless Constructor?
C#
Constructor
Javascript: Mocking Constructor using Sinon
Javascript
Unit Testing
Constructor
Mocking
Sinon
Creating a named list from two vectors (names, values)
R
List
Constructor
Lapply
Named
In C#, do you need to call the base constructor?
C#
Inheritance
Constructor
extends of the class with private constructor
Java
Constructor
How can I have an overloaded constructor call both the default constructor as well as an overload of the base constructor?
C#
Constructor
Why doesn't JavaScript ES6 support multi-constructor classes?
Javascript
Class
Constructor
Ecmascript 6
Abstract constructor in C#
C#
.Net
Constructor
Abstract Class
A most vexing parse error: constructor with no arguments
C++
Constructor
Standards
How to overload constructor of an Object in JS (Javascript)?
Javascript
Constructor
Overriding
C# - Making all derived classes call the base class constructor
C#
Inheritance
Constructor
Setter methods or constructors
Java
Constructor
Setter
What is Array.apply actually doing
Javascript
Arrays
Constructor
Throwing ArgumentNullException in constructor?
C#
Exception
Constructor
Null
Arguments
How to initialize member-struct in initializer list of C++ class?
C++
List
Constructor
Struct
Initializer
__init__ as a constructor?
Python
Constructor
Initialization
Can I initialize an STL vector with 10 of the same integer in an initializer list?
C++
Stl
Constructor
Initializer List
Who deletes the memory allocated during a "new" operation which has exception in constructor?
C++
Exception
Memory Leaks
Constructor
call to pure virtual function from base class constructor
C++
Constructor
Abstract Class
Object Lifetime
Pure Virtual
Asynchronous constructor
Javascript
node.js
Asynchronous
Constructor
Chain-calling parent initialisers in python
Python
Oop
Inheritance
Constructor
Get argument types for function / class constructor
Typescript
Types
Constructor
Initialize multiple constant class members using one function call C++
C++
Oop
Constructor
Constants
Initializer List
How much work should be done in a constructor?
Oop
Constructor
Calling Overridden Constructor and Base Constructor in C#
C#
Constructor
PHP constructor to return a NULL
Php
Constructor
Error Handling
Null
How do I create a C# array using Reflection and only type info?
C#
Arrays
Reflection
Constructor
Returning a value in constructor function of a class
Php
Oop
Class
Constructor
scala class constructor parameters
Scala
Constructor
Scope
Immutability
Inheriting constructors
C++
Inheritance
Gcc
Constructor
Is it not possible to define multiple constructors in Python?
Python
Constructor
What is the reason to use the 'new' keyword at Derived.prototype = new Base
Javascript
Constructor
Prototype
C# inheritance and default constructors
C#
Oop
Constructor
Why do we not have a virtual constructor in C++?
C++
Constructor
Virtual Functions
Call one constructor from another
C#
Constructor
difference between variables inside and outside of __init__()
Python
Class
Oop
Constructor
Calling virtual functions inside constructors
C++
Constructor
Overriding
Virtual Functions
Spring @Autowire on Properties vs Constructor
Spring
Dependency Injection
Constructor
Autowired
Constructors in Go
Oop
Constructor
Go
Can I use Class.newInstance() with constructor arguments?
Java
Constructor
How do I get a PHP class constructor to call its parent's parent's constructor?
Php
Class
Oop
Inheritance
Constructor
Do the parentheses after the type name make a difference with new?
C++
Constructor
Initialization
New Operator
C++ Faq
Can I call a constructor from another constructor (do constructor chaining) in C++?
C++
Constructor
How to do constructor chaining in C#
C#
Constructor
Constructor Chaining
ReactJS: Warning: setState(...): Cannot update during an existing state transition
Reactjs
Constructor
Setstate
Should I instantiate instance variables on declaration or in the constructor?
Java
Constructor
Instance Variables
Call asynchronous method in constructor?
C#
Windows Phone-8
Constructor
Visual Studio-2013
Async Await
When is it right for a constructor to throw an exception?
Exception
Language Agnostic
Constructor
Can a constructor in Java be private?
Java
Constructor
Private
Constructor of an abstract class in C#
C#
Constructor
Abstract Class
Can constructors throw exceptions in Java?
Java
Exception
Constructor
Accessing constructor of an anonymous class
Java
Constructor
Overloading
Anonymous Types
Can I call an overloaded constructor from another constructor of the same class in C#?
C#
Constructor
Default constructor with empty brackets
C++
Constructor
Default Constructor
C++ Faq
Most Vexing-Parse
What is the function __construct used for?
Php
Constructor
Java Constructor Inheritance
Java
Inheritance
Constructor
Instance attribute attribute_name defined outside __init__
Python
Constructor
Pylint
How does interfaces with construct signatures work?
Typescript
Constructor
Interface
What does the explicit keyword mean?
C++
Constructor
Explicit
C++ Faq
Explicit Constructor
What is a clean "pythonic" way to implement multiple constructors?
Python
Class
Constructor
How to initialize HashSet values by construction?
Java
Collections
Constructor
Initialization
Hashset
Is it good practice to make the constructor throw an exception?
Java
Exception
Constructor
What's the difference between an object initializer and a constructor?
C#
.Net
Constructor
Object Initializer
How to inherit constructors?
C#
Inheritance
Constructor
Does the default constructor initialize built-in types?
C++
Constructor
Initialization
Default Constructor
Built in-Types
Is there a generic constructor with parameter constraint in C#?
C#
Generics
Parameters
Constructor
Generic Constraints
How does the const constructor actually work?
Dart
Constructor
Is it better to use Enumerable.Empty<T>() as opposed to new List<T>() to initialize an IEnumerable<T>?
C#
Linq
Constructor
Is it bad practice to have a constructor function return a Promise?
Javascript
node.js
Architecture
Constructor
Promise
What are the rules for calling the base class constructor?
C++
Inheritance
Constructor
Is it unnecessary to put super() in constructor?
Java
Constructor
Super
Why can't the C# constructor infer type?
C#
Generics
Constructor
Type Inference
Java default constructor
Java
Constructor
Default Constructor
typeof for RegExp
Javascript
Regex
Constructor
Instanceof
Typeof
Code snippet or shortcut to create a constructor in Visual Studio
C#
Visual Studio
Constructor
Code Snippets
Shortcut
Understanding prototypal inheritance in JavaScript
Javascript
Oop
Inheritance
Constructor
Prototype Programming
How many constructor arguments is too many?
Parameters
Refactoring
Constructor
Coding Style
Can an abstract class have a constructor?
Java
Constructor
Abstract Class
What is the difference between using constructor vs getInitialState in React / React Native?
Reactjs
React Native
Constructor
C# constructor execution order
C#
Inheritance
Constructor
Constructor Chaining
Python constructor and default value
Python
Constructor
Default Value
How do I call one constructor from another in Java?
Java
Constructor
Why do this() and super() have to be the first statement in a constructor?
Java
Constructor
Default constructor vs. inline field initialization
Java
Oop
Constructor
Calling constructor from other constructor in same class
C#
Constructor
Initialize parent's protected members with initialization list (C++)
C++
Inheritance
Constructor
Initialization List
C# static class constructor
C#
Class
Static
Constructor
C# Error: Parent does not contain a constructor that takes 0 arguments
C#
Inheritance
Constructor
Compiler Errors
Kotlin secondary constructor
Syntax
Constructor
Kotlin
Is a `=default` move constructor equivalent to a member-wise move constructor?
C++
C++11
Constructor
Default
Move Semantics
Is there a way to @Autowire a bean that requires constructor arguments?
Spring
Constructor
Autowired
Spring Annotations
Spring Bean
How to call Base Class's __init__ method from the child class?
Python
Python 2.7
Inheritance
Constructor
Why should the copy constructor accept its parameter by reference in C++?
C++
Constructor
Copy
Copy Constructor
C++ template constructor
C++
Templates
Constructor
Default parameters with C++ constructors
C++
Constructor
Coding Style
Overloading
Java Lombok: Omitting one field in @AllArgsConstructor?
Java
Syntax
Constructor
Field
Lombok
Understanding Factory constructor code example - Dart
Constructor
Dart
What do constructor type arguments mean when placed *before* the type?
Java
Generics
Syntax
Constructor
Generic Type-Argument
Interface defining a constructor signature?
C#
Interface
Constructor
Javascript "Not a Constructor" Exception while creating objects
Javascript
Object
Constructor
Typeerror
Creating an object: with or without `new`
C++
Constructor
New Operator
Destructor
How do I call a super constructor in Dart?
Inheritance
Constructor
Dart
Superclass
Extends
Will the base class constructor be automatically called?
C#
Constructor
Base Class
Hide Utility Class Constructor : Utility classes should not have a public or default constructor
Java
Constructor
Sonarqube
async constructor functions in TypeScript?
Constructor
Typescript
Async Await
How do I initialize a final class property in a constructor?
Constructor
Dart
Final
Automapper - how to map to constructor parameters instead of property setters
Constructor
Automapper
What is an initialization block?
Java
Constructor
Initialization
Initialization Block
Creating an instance of class
C++
Class
Constructor
What is the significance of the Javascript constructor property?
Javascript
Prototype
Constructor
What is the best way to give a C# auto-property an initial value?
C#
Constructor
Getter
Setter
Automatic Properties
Is there an alternative to bastard injection? (AKA poor man's injection via default constructor)
C#
.Net
Oop
Dependency Injection
Constructor
How to detect if a function is called as constructor?
Javascript
Constructor
Why can't I overload constructors in PHP?
Php
Oop
Overloading
Constructor
Inheritance with base class constructor with parameters
C#
Inheritance
Constructor
Constructor overloading in Java - best practice
Java
Constructor
Overloading
Constructor Overloading
Is passing a C++ object into its own constructor legal?
C++
Class
Constructor
Language Lawyer
Undefined Behavior
What is difference between instantiating an object using new vs. without
C++
Constructor
New Operator
Dual emission of constructor symbols
C++
Gcc
Constructor
C# : assign data to properties via constructor vs. instantiating
C#
Oop
Constructor
Properties
Overload constructor for Scala's Case Classes?
Scala
Constructor
Overloading
Scala 2.8
Case Class
How to start an Intent by passing some parameters to it?
Android
Constructor
Android Intent
How do I check if a type provides a parameterless constructor?
C#
.Net
Reflection
Constructor
Types
Horrendous performance & large heap footprint of Java 8 constructor reference?
Java
Constructor
Java 8
Out of-Memory
Method Reference
Struct constructor: "fields must be fully assigned before control is returned to the caller."
C#
Constructor
Struct
Constructor overload in TypeScript
Typescript
Constructor
Overloading
Class constructor type in typescript?
Class
Typescript
Types
Constructor
Use of Initializers vs Constructors in Java
Java
Constructor
Initializer
Static Initializer
Initialization Block
Copy constructor in python?
Python
Constructor
Copy
'UserControl' constructor with parameters in C#
C#
Winforms
Parameters
Constructor
User Controls
Using C# reflection to call a constructor
C#
Reflection
Constructor
Static class initializer in PHP
Php
Class
Static
Constructor
Initializer
How can I initialize C++ object member variables in the constructor?
C++
Constructor
Class Members
Object Construction
What are practical uses of a protected constructor?
C++
Constructor
Protected
Colon after Constructor in dart
Constructor
Dart
Flutter
How to use base class's constructors and assignment operator in C++?
C++
Inheritance
Constructor
Assignment Operator
C# member variable initialization; best practice?
C#
Constructor
Declaration
What does a colon following a C++ constructor name do?
C++
Constructor
Initialization List
Ctor Initializer
C++: Where to initialize variables in constructor
C++
Constructor
Initialization
Why is Class.newInstance() "evil"?
Java
Constructor
Runtime
Instantiation
DataContractSerializer doesn't call my constructor?
C#
.Net
Constructor
Serialization
Datacontractserializer
base() and this() constructors best practices
C#
Oop
Inheritance
Constructor
Instantiation
ES6: call class constructor without new keyword
Javascript
Constructor
Ecmascript 6
Instance
When do you need to explicitly call a superclass constructor?
Java
Constructor
Subclass
Superclass
In what order do static blocks and initialization blocks execute when using inheritance?
Java
Inheritance
Constructor
Static Block
Use of .apply() with 'new' operator. Is this possible?
Javascript
Oop
Class
Inheritance
Constructor
Why do constructors not return values?
Constructor
How to invoke the super constructor in Python?
Python
Class
Inheritance
Constructor
Superclass
Angular 2 Component Constructor Vs OnInit
Angular
Constructor
Ngoninit
What is the difference between init block and constructor in kotlin?
Kotlin
Constructor
Initialization Block
Private Constructor in Python
Python
Static
Constructor
Private
Calling an async method from component constructor in Dart
Asynchronous
Constructor
Dart
Default member values best practice
C++
Constructor
C++11
Header Files
Default Value
Is it important to unit test a constructor?
C#
.Net
Unit Testing
Constructor
Pass arguments to Constructor in VBA
Vba
Class
Oop
Constructor
Factory
Struct Constructor in C++?
C++
Struct
Constructor
What does calling super() in a React constructor do?
Javascript
Reactjs
Constructor
Ecmascript 6
What values can a constructor return to avoid returning this?
Javascript
Constructor
New Operator
JUnit: using constructor instead of @Before
Constructor
Junit
Initialization
Best way to handle multiple constructors in Java
Java
Constructor
Field
Instantiate a class object with constructor that accepts a string parameter?
Java
Html
Reflection
Constructor
Initialize a static final field in the constructor
Java
Static
Constructor
Final
Leaking this in constructor warning
Java
Netbeans
Constructor
This
Netbeans 6.9
How do I call the base class constructor?
C++
Constructor
Is it possible to create constructor-extension-method ? how?
C#
Constructor
Extension Methods
Why can't constructors be final, static, or abstract?
Java
Syntax
Constructor
What destructors are run when the constructor throws an exception?
C++
Constructor
Exception Handling
Destructor
Object array initialization without default constructor
C++
Arrays
Constructor
Has the new C++11 member initialization feature at declaration made initialization lists obsolete?
C++
C++11
Constructor
Initialization
Declaration
How to extend a class that has multiple constructors in Kotlin?
Constructor
Kotlin
Private constructor in Kotlin
Java
Constructor
Kotlin
Visibility
In C++ can constructor and destructor be inline functions?
C++
Constructor
Destructor
How can I access a private constructor of a class?
Java
Oop
Constructor
Instance
Cannot reference "X" before supertype constructor has been called, where x is a final variable
Java
Constructor
Final
Supertype
When is a custom attribute's constructor run?
C#
.Net
vb.net
Constructor
Attributes
Java constructor style: check parameters aren't null
Java
Constructor
Null
Coding Style
Why can't enum constructors be protected or public in Java?
Java
Enums
Constructor
Java: accessing private constructor with type parameters
Java
Reflection
Constructor
Private
Is the default Move constructor defined as noexcept?
C++
C++11
Constructor
Move Semantics
Calling a constructor to re-initialize object
C++
Constructor
C++ Abstract Class: constructor yes or no?
C++
Class
Constructor
Abstract
What is a non-trivial constructor in C++?
C++
Constructor
How to initialize a const field in constructor?
C++
Constructor
Constants
Ctor Initializer
Should constructors comply with the Liskov Substitution Principle?
Constructor
Class Method
Liskov Substitution-Principle
Are fields initialized before constructor code is run in Java?
Java
Constructor
Initialization
Will an 'empty' constructor or destructor do the same thing as the generated one?
C++
Class
Oop
Constructor
Destructor
Calling the base constructor in C#
C#
.Net
Inheritance
Constructor
Can constructors be async?
C#
Constructor
Async Await
What is this weird colon-member (" : ") syntax in the constructor?
C++
Syntax
Constructor
C++ Faq
Ctor Initializer
Can constructor return a null object?
Java
Constructor
Null
How to set @Autowired constructor params as "required=false" individually
Spring
Spring Boot
Constructor
Autowired
What's wrong with overridable method calls in constructors?
Java
Oop
Inheritance
Constructor
Overriding
Is there a way to instantiate a class without calling __init__?
Python
Class
Constructor
Instantiation
How to overload __init__ method based on argument type?
Python
Constructor
Operator Overloading
Can I use identical names for fields and constructor parameters?
C++
Parameters
Constructor
Python: Inherit the superclass __init__
Python
Inheritance
Constructor
Init
Using "Object.create" instead of "new"
Javascript
Constructor
New Operator
Object Create
Conversion constructor vs. conversion operator: precedence
C++
Constructor
Operators
Type Conversion
Conversion Operator
Is doing a lot in constructors bad?
Java
Constructor
Best way to do multiple constructors in PHP
Php
Constructor
Multiple Constructors
C++ Constructor/Destructor inheritance
C++
Inheritance
Constructor
Destructor
Do you use TestInitialize or the test class constructor to prepare each test? and why?
.Net
Unit Testing
Constructor
C# constructors overloading
C#
Constructor
Constructor Overloading
C++: constructor initializer for arrays
C++
Constructor
Initializer
Why won't this compile without a default constructor?
C++
Constructor
Scope
Default Constructor
Most Vexing-Parse
__construct() vs SameAsClassName() for constructor in PHP
Php
Constructor
Why must const members be initialized in the constructor initializer rather than in its body?
C++
Constructor
Initialization
Constants
How can I force a Constructor to be defined in all subclass of my abstract class
Java
Constructor
Abstract
Using C++ base class constructors?
C++
Inheritance
Constructor
C++11
Can Kotlin data class have more than one constructor?
Constructor
Kotlin
Why can't Java constructors be synchronized?
Java
Constructor
Language Design
Synchronized
Serialize JavaScript object into JSON string
Javascript
Json
Constructor
What is the difference between getDeclaredConstructors and getConstructors in the Class API?
Java
Reflection
Constructor
Why do C++ objects have a default destructor?
C++
Constructor
Destructor
Default Constructor
What is constructor inheritance?
C++
Inheritance
Constructor
C++11
How to call the constructor with call_user_func_array in PHP
Php
Constructor
What is the use of static constructors?
C#
Constructor
Static Constructor
Destructors of builtin types (int, char etc..)
C++
Constructor
Destructor
Typedef
Why do abstract classes in Java have constructors?
Java
Constructor
Abstract Class
How to force deletion of a python object?
Python
Constructor
Garbage Collection
Destructor
Reference Counting
a constructor as a delegate - is it possible in C#?
C#
Delegates
Constructor
How to create constructor of custom view with Kotlin
Android
Constructor
Kotlin
Why can't I create an abstract constructor on an abstract C# class?
C#
Inheritance
Oop
Constructor
Abstract Class
Is there an implicit default constructor in C++?
C++
Constructor
Rule-of-Three becomes Rule-of-Five with C++11?
C++
Constructor
C++11
Rvalue Reference
Rule of-Three
Multiple constructors: the Pythonic way?
Python
Constructor
Initialization
Initializer
Idioms
How to make the class constructor private in Ruby?
Ruby
Constructor
Access Specifier
Virtual member call in a constructor
C#
Constructor
Warnings
Resharper
Virtual Functions
Sending reference of object before its construction
C#
Reference
Constructor
Constructor vs Object Initializer Precedence in C#
C#
Constructor
Object Initializers
Data Constructor promotion in GHC-7.6
Haskell
Constructor
Ghc
How do I call New-Object for a constructor which takes a single array parameter?
Arrays
Powershell
Parameters
Constructor
Default constructors in Java
Java
Inheritance
Constructor
Changed rules for protected constructors in C++17?
C++
Constructor
Language Lawyer
C++17
Protected
The copy constructor and assignment operator
C++
Constructor
Operators
Copy Constructor
Assignment Operator
Call one constructor from the body of another in C#
C#
Constructor
new Backbone.Model() vs Backbone.Model.extend()
Javascript
backbone.js
Constructor
Instance
Infinite loop in constructor without for or while
C++
Recursion
Constructor
Constants
Initializing a union with a non-trivial constructor
C++
Constructor
Multiplatform
What setup code should go in Form Constructors versus Form Load event?
C#
Winforms
Constructor
Onload Event
In Scala, how can I subclass a Java class with multiple constructors?
Java
Scala
Constructor
Multiple Constructors
What if I write return statement in constructor?
C++
Constructor
Return Value
Return
Return Type
PHP constructor with a parameter
Php
Constructor
Select class constructor using enable_if
C++
Templates
Constructor
Sfinae
Transfer NULL to the constructor
C#
Constructor
Overloading
Constructor Overloading
C++ virtual function from constructor
C++
Oop
Class
Constructor
Virtual
Throwing exceptions from constructors
C++
Exception
Constructor
Throw
What is a converting constructor in C++ ? What is it for?
C++
Constructor
Copy Constructor
What is the order in which the destructors and the constructors are called in C++
C++
Constructor
Destructor
C++, is it possible to call a constructor directly, without new?
C++
Constructor
Placement New
JavaScript: The Good Parts - How to not use `new` at all
Javascript
Oop
Constructor
New Operator
When do we need a private constructor in C++?
C++
Constructor
Private
Defining an object without calling its constructor in C++
C++
Class
Object
Constructor
Creating a Fragment: constructor vs newInstance()
Android
Constructor
Android Fragments
Default Constructor
How many objects are created due to inheritance in java?
Java
Object
Constructor
undefined reference to 'vtable for class' constructor
C++
Class
Constructor
Do constructors always have to be public?
Java
Oop
Design Patterns
Constructor
Access Modifiers