The page I am working on has a javascript function executed to print parts of the page. For some reason, printing in Safari, causes the window to somehow update. I say somehow, because it does not really refresh as in reload the page, but rather it starts the "rendering" of the page from start, i.e. scroll to top, flash animations start from 0, and so forth. The effect is reproduced by this fiddle: http://jsfiddle.net/fYmnB/ Clicking the print button and finishing or cancelling a print in Safari causes the screen to "go white" for a sec, which in my real website manifests itself as something "like" a reload. While running print button with, let's say, Firefox, just opens and closes the print dialogue without affecting the fiddle page in any way. Is there something with my way of calling the browsers print method that causes this, or how can it be explained - and preferably, avoided? P.S.: On my real site the same occurs with Chrome. In the ex
One point is that it will execute whichever constructor is called. If you have several constructors and they don't call each other (for whatever reason, e.g. each wanting to call a directly-corresponding superclass constructor) this is one way of making sure the same code is executed for all constructors, without putting it in a method which could be called elsewhere.
ReplyDeleteIt's also potentially useful when you're writing an anonymous class - you can't write a constructor, but you can write an initializer block. I've seen this used for JMock tests, for example.
It's called an initializer block.
ReplyDeleteThe Java compiler copies initializer blocks into every constructor. Therefore, this approach can be used to share a block of code between multiple constructors.
It called init block. In such block you can perform logic that are same for all constructions also you can separate declaration and initialization of same fields.
ReplyDeleteupd and of course double brace initialization, like
List<Integer> answers = new ArrayList<Integer>(){{add(42);}}
This is an initialization block. As mentioned by Matt Ball, they are copied into each constructor.
ReplyDeleteYou might be interested to know about static initialization blocks (also in Matt's link):
public class Foo {
static {
System.out.println("class Foo just got initialized!");
}
{
System.out.println("an instance of Foo just got initialized!");
}
}