difference between single slit diffraction and double slit diffraction

guys im a little bit confused about the path difference at the first minimum for single slit diffraction and double slit diffraction. On some sources online its saying that the path difference for single slit at the minimum is one wavelength but half a wavelength for double. I don't get how its a full wavelength because wouldn't it interfere constructively. can someone clarify if im understanding this correctly.