Programming Technique: How to create a simple card game

Question

as I am learning the Ruby language, I am getting closer to actual programming. I was thinking of creating a simple card game. My question isn\'t Ruby oriented, but I do kno

Answer 1

Rather than cramming this all in a comment, I'm adding this as a note for people that might find it useful. Ruby 1.9's native Array#shuffle! and Array#shuffle does in fact use the Knuth-Fisher-Yates shuffle algorithm.

ruby-1.9.1-p376/array.c

/*
 *  call-seq:
 *     array.shuffle!        -> array
 *  
 *  Shuffles elements in _self_ in place.
 */

static VALUE
rb_ary_shuffle_bang(VALUE ary)
{
    long i = RARRAY_LEN(ary);

    rb_ary_modify(ary);
    while (i) {
    long j = rb_genrand_real()*i;
    VALUE tmp = RARRAY_PTR(ary)[--i];
    RARRAY_PTR(ary)[i] = RARRAY_PTR(ary)[j];
    RARRAY_PTR(ary)[j] = tmp;
    }
    return ary;
}


/*
 *  call-seq:
 *     array.shuffle -> an_array
 *  
 *  Returns a new array with elements of this array shuffled.
 *     
 *     a = [ 1, 2, 3 ]           #=> [1, 2, 3]
 *     a.shuffle                 #=> [2, 3, 1]
 */

static VALUE
rb_ary_shuffle(VALUE ary)
{
    ary = rb_ary_dup(ary);
    rb_ary_shuffle_bang(ary);
    return ary;
}