Almost periodic solutions of differential equations are more general than periodic solutions

so almost periodic solutions will be studied on a class secondorder differential equations with piecewise constant argument. A class of nonhomogeneous difference equations are constructed by the continuity of solutions at the integer point of this class of equations. The existence of almost periodic solutions and the uniqueness of this kind of solutions on this class of equations are investigated by using of eigenvalue of corresponding homogeneous difference equations

almost periodic sequence solutions of relevant difference equations and some properties of almost periodic functions and almost periodic sequences.