Start or stop expression at a given frame

I'm sure there is a way to stop the wiggle at the frame number 100, or time elapsed, Dan an others would know. But you can also add a Slider (Effect > Expression Controls > Slider Control) to a new Null layer, then highlight either the Amplitude or Frequency,
in your wiggle expression and pickwhip that to the slider, you get an expression like this:

wiggle (5,thisComp.layer("Null 1").effect("Slider Control")("Slider"))

I started out with:
wiggle (5, 50)

and pickwhipped the 50 (Amplitude I think). Anyway either will work and when you set a keyframe of "0" on the slider at 100 frames.
it stops that wiggle dead in its tracks, and more keyframes down the line will restart that wiggle. Oh, you need to set a keyframe >0 before 100 frames so it will wiggle before.

Anyway it works and is very controllable, an changeable.

God luck.

Thanks for the fast reply,

But isnt there something i am missing, i mean there must be some
kind of stop(); for an expression. What if i rotate something with steps
of 10 each time. And i want to let it wiggle its position at frame 40. Then it will never stop rotating and it will rotate and wiggle instead of only wiggling and not rotating.

Am i thinking in the wrong way ? do such things have to been done with sliders ?

Thanks!

Sorry
if (time < 4 ) wiggle (3,10) else value

Thanks for the replies.

Im starting to get a hang on it.
Sliders is the way to go to adjust expressions over time.

thanks