it doesnt matter 后面能接if吗,如果能,请给我详细的说明.并有例句.

完全可以,和whether意思一样,表示“是否”,甚至比whether还要常用.如：
it doesn't matter if she apologize or not.√
it doesn't matter whether she apologize or not.√
但这种从句置于句首时,不能用if,只能用whether.
if she apologize or not doesn't matter.X
whether she apologize or not doesn't matter.√
另外,一般来说,if不能紧跟or not,而whether则可以,如：
it doesn't matter if or not she apologize.X
it doesn't matter whether or not she apologize.√
以上规则纯属约定俗成,没什么道理,记住即可.

It doesn't matter whether....
这是形式主语的句子，真正的主语从句是whether.... ,主语从句只能用whether 引导，不能用if 的。