Initializers are called to create a new instance of a particular type. In its simplest form, an initializer is like an instance method with no parameters
Questions tagged [initializer]
684 questions
192
votes
23 answers
static constructors in C++? I need to initialize private static objects
I want to have a class with a private static data member (a vector that contains all the characters a-z). In java or C#, I can just make a "static constructor" that will run before I make any instances of the class, and sets up the static data…
Gordon Gustafson
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138
votes
4 answers
Initializer is inaccessable due to 'internal' protection level
I have a protocol
LoginStrategy
public protocol LoginStrategy {
func login(_ viewController: UIViewController)
func getUserInfo(withCompletionHandler completionHandler: @escaping (_ userInfo: [String: Any]?) -> ())
func…
Twitter khuong291
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129
votes
5 answers
Why are C# 3.0 object initializer constructor parentheses optional?
It seems that the C# 3.0 object initializer syntax allows one to exclude the open/close pair of parentheses in the constructor when there is a parameterless constructor existing. Example:
var x = new XTypeName { PropA = value, PropB = value };
As…
James Dunne
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113
votes
10 answers
Use of Initializers vs Constructors in Java
So I've been brushing up on my Java skills as of late and have found a few bits of functionality that I didn't know about previously. Static and Instance Initializers are two such techniques.
My question is when would one use an initializer instead…
Inertiatic
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113
votes
9 answers
Static class initializer in PHP
I have an helper class with some static functions. All the functions in the class require a ‘heavy’ initialization function to run once (as if it were a constructor).
Is there a good practice for achieving this?
The only thing I thought of was…
user258626
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103
votes
8 answers
Calling a Java method with no name
I'm looking at the code below and found something a bit strange:
public class Sequence {
Sequence() {
System.out.print("c ");
}
{
System.out.print("y ");
}
public static void main(String[] args) {
new…
David
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99
votes
2 answers
Static initialisation block in Kotlin
What is the equivalent of a static initialisation block in Kotlin?
I understand that Kotlin is designed to not have static things. I am looking for something with equivalent semantics - code is run once when the class is first loaded.
My specific…
Marcin Koziński
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77
votes
2 answers
Objective-C: init vs initialize
In Objective-C, what is the difference between the init method (i.e. the designated initializer for a class) and the initialize method? What initialization code should be put in each?
jrdioko
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76
votes
14 answers
C++: constructor initializer for arrays
I'm having a brain cramp... how do I initialize an array of objects properly in C++?
non-array example:
struct Foo { Foo(int x) { /* ... */ } };
struct Bar {
Foo foo;
Bar() : foo(4) {}
};
array example:
struct Foo { Foo(int x) { /*…
Jason S
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73
votes
3 answers
Static constructor equivalent in Objective-C?
I'm new to Objective C and I haven't been able to find out if there is the equivalent of a static constructor in the language, that is a static method in a class that will automatically be called before the first instance of such class is…
Franklin Munoz
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65
votes
7 answers
Multiple constructors: the Pythonic way?
I have a container class that holds data. When the container is created, there are different methods to pass data.
Pass a file which contains the data
Pass the data directly via arguments
Don't pass data; just create an empty container
In Java, I…
Johannes
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60
votes
5 answers
In Ruby, what's the relationship between 'new' and 'initialize'? How to return nil while initializing?
What I want is:
obj = Foo.new(0) # => nil or false
This doesn't work:
class Foo
def initialize(val)
return nil if val == 0
end
end
I know in C/C++/Java/C#, we cant return a value in a constructor.
But I'm wondering whether it is possible…
Chris Xue
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55
votes
2 answers
How to initialize member-struct in initializer list of C++ class?
I have the following class definitions in c++:
struct Foo {
int x;
char array[24];
short* y;
};
class Bar {
Bar();
int x;
Foo foo;
};
and would like to initialize the "foo" struct (with all its members) to zero in the initializer of…
Jan Rüegg
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53
votes
4 answers
Is an empty initializer list valid C code?
It is common to use {0} to initialize a struct or an array but consider the case when the first field isn't a scalar type. If the first field of struct Person is another struct or array, then this line will result in an error (error: missing braces…
Marcus Ahlberg
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51
votes
4 answers
How to handle a static final field initializer that throws checked exception
I am facing a use case where I would like to declare a static finalfield with an initializer statement that is declared to throw a checked exception. Typically, it'd look like this:
public static final ObjectName OBJECT_NAME = new…
Romain
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