In this paper we study the growth and -approximation, 1 ≤ ≤ ∞, of solutions (not necessarily entire) of Helmholtz-type equations. Moreover, we obtain the characterization of order and type of ∈ , 0 < < ∞, in terms of decay of approximation errors ( , 0 ) and , ( , 0 ), = 1, 2. Our results extend and improve the results obtained by McCoy [13].