End of Life Ruby 3.1 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

instance method

NilClass#to_r

nil.to_r → (0/1)

static VALUE
nilclass_to_r(VALUE self)
{
    return rb_rational_new1(INT2FIX(0));
}

Returns zero as a rational.

See also #to_i #to_s #to_h also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.0