How does the wavelength of light change when passing from the first medium to the second?

When light passes from one medium to another, the wavelength λ changes as follows:
1) from a less optically dense medium to a more optically dense medium, the wavelength λ decreases, the frequency f does not change, the propagation velocity is determined by the formula ν = λ * f also decreases.
2) from a more optically dense medium to a less optically dense medium, the wavelength λ increases, the frequency f does not change, the propagation velocity is determined by the formula ν = λ * f and also increases.
In a denser environment, it is more difficult for the wave to travel the distance.