if i buy a stock a couple days before the date which they give out

[Frosty Z]

dividends, do i get the dividend? if i buy a stock a couple days before the date which they give out dividends, do i get the dividend?

if so, do i buy stock before the ex-dividend date ??
technically, is it a good idea to buy a stock before its ex-dividend date and then once you collect that big dividend, you quickly sell the stock?? so then , you are able to make a quick profit this way?