why in AC operation of capacitor current lead our voltage and in inductor voltage lead our current?

had the same problem but found i just hadnt turned the plug on at the wall

Let us deal with the capacitor first.
Upon switch on, the plates are not charged so the current is a maximum, after a period of time, the plates charge thereby limiting the current flow. Hence the current leads the voltage.

Now for the inductor, this is a little harder.
Need to remember that when a conductor is cut by magnetic flux, an induced emf is created. This induced emf creates an induced current which will flow in the opposite direction to the cause which produced it. (Lenz's law).
Upon switch on, the voltage is at a max as the current is being limited by the induced current. After a period of time the current builds up but then the a.c. waveform changes direction so the process starts all over again. Hence, the current lags the voltage.