initialize category fields constructor during declaration?

i've programming c# java recently i am extraordinary where best place initialize category fields.

should i during declaration?:

public category dice
{
    private int topface = 1;
    private futile myrand = new random();

    open vacant roll()
    {
       // ......
    }
}

or constructor?:

public category dice
{
    private int topface;
    private futile myrand;

    open dice()
    {
        topface = 1;
        myrand = new random();
    }

    open vacant roll()
    {
        // .....
    }
}

i'm unequivocally extraordinary veterans cruise best practice. i wish unchanging hang approach.