6.5. Static Initialization

Java: static initializer block, called before the first instance is created or any static members are referenced

public class Foo {
    static {
        System.out.println("Static initializer block invoked.");
    }
}

Vala: static construct { } block. The first time that a class, or any subclass of it, is instantiated, this code is run. It is guaranteed that this code will run exactly once in a program where such a class is used.

class Foo : Object {
    static construct {
        stdout.printf ("Static constructor invoked.\n");
    }
}

Additionally a Vala class can have a class construct { } block. This block will be executed once at the first use of its class, and once at the first use of each subclass of this class.