Using randoms and super

Question

How would I call a Random from java.util.Random into a supertype constructor?

For example

Random rand = new Random();
int randomValue = rand.nextInt(10) + 5;

public Something() 
{
    super(randomValue);
    //Other Things
}

When I try this the compiler says that I "cannot reference randomValue before supertype constructor has been called".

Answer 1

The super() call must be the first call in the constructor, and any expressions that initialize instance variables will only be evaluated after the super call returns. Therefore super(randomValue) attempts to pass the value of a variable not yet declared to the super class's constructor.

A possible solution is to make rand static (it makes sense to have a single random number generator for all instances of your class) and generate the random number in the constructor :

static Random rand = new Random();

public Something() 
{
    super(rand.nextInt(10) + 5);
    //Over Things
}