Riesz–Zygmund means and trigonometric approximation in Morrey spaces

We estimate best approximations and moduli of smoothness of functions in Morrey spaces variable exponent spaces by norms of derivatives of Riesz–Zygmund means and partial Fourier sums in these spaces. As a consequence, we obtain a description of Hölder spaces based on the Morrey spaces. The direct results on approximation in these Hölder spaces are also obtained.