Do charity shops wash clothes before they are sold?

[upandleftthenright]

I donate a lot of clothes etc to charity shops and always wash and iron everything beforehand but a friend said the shops wash everything anyway and I might as well just bundle them up in black bin bags. I could ask in the shops but don’t have a drop off scheduled any time soon.

like @Facade1983 I also wonder about quality clothing that requires dry cleaning, such as suits, coats, jackets, expensive dresses and the like, where the dry cleaning might cost as much as the item might sell for.

Do charity shops spot clean a not quite pristine collar or cuff, or would the garment be binned?