If you don’t like static blocks (some people don’t) then an alternative is to use a static method. IIRC, Josh Bloch recommended this (apparently not in Effective Java on quick inspection). public static final ObjectName OBJECT_NAME = createObjectName(“foo:type=bar”); private static ObjectName createObjectName(final String name) { try { return new ObjectName(name); } catch (final SomeException exc) … Read more
No, an empty initializer list is not allowed. This can also be shown by GCC when compiling with -std=c99 -pedantic: a.c:4: warning: ISO C forbids empty initializer braces The reason is the way the grammar is defined in §6.7.9 of the 2011 ISO C Standard: initializer: assignment-expression { initializer-list } { initializer-list , } initializer-list: … Read more
First of all, you should (must !) read this c++ faq regarding POD and aggregates. In your case, Foo is indeed a POD class and foo() is a value initialization : To value-initialize an object of type T means: if T is a class type (clause 9) with a user-declared constructor (12.1), then the default … Read more
In Ruby, what’s the relationship between ‘new‘ and ‘initialize‘? new typically calls initialize. The default implementation of new is something like: class Class def new(*args, &block) obj = allocate obj.initialize(*args, &block) # actually, this is obj.send(:initialize, …) because initialize is private obj end end But you can, of course, override it to do anything you … Read more
You can’t have multiple methods with same name in Python. Function overloading – unlike in Java – isn’t supported. Use default parameters or **kwargs and *args arguments. You can make static methods or class methods with the @staticmethod or @classmethod decorator to return an instance of your class, or to add other constructors. I advise … Read more
The +initialize method is called automatically the first time a class is used, before any class methods are used or instances are created. You should never call +initialize yourself. I also wanted to pass along a tidbit I learned that can bite you down the road: +initialize is inherited by subclasses, and is also called … Read more
Edit: see Barry’s answer for something more recent, there was no way when I answered but nowadays you are rarely limited to C++98. There is no way. You need a default constructor for array members and it will be called, afterwards, you can do any initialization you want in the constructor.
-init is an instance method, used to initialize a particular object. +initialize is a class method, run before any instances of the class are created and before other class methods are run. +initialize isn’t something you use most of the time, but it’s handy for setting up any static variables that the class as a … Read more
From some point of view, companion objects in Kotlin are equivalent to static parts of Java classes. Particularly, they are initialized before class’ first usage, and this lets you use their init blocks as a replacement for Java static initializers: class C { companion object { init { //here goes static initializer code } } … Read more
This: static { System.out.print(“x “); } is a static initialization block, and is called when the class is loaded. You can have as many of them in your class as you want, and they will be executed in order of their appearance (from top to bottom). This: { System.out.print(“y “); } is an initialization block, … Read more