How to Stop Automatically Posts on your Facebook Wall or in Groups

If you found any nude or Pornography pics ,links or videos posted by you on your facebook Wall , in facebook comments or in facebook groups but you don't post them yourself then here is a solution to stop this.
this is because of some Apps on facebook that u like.These Apps post on your behalf on your Wall or in Groups.
Follow these Steps 
Step1 : Go to Setting
Step2 : Click on "Apps"
Step3 : Now remove all unwanted Apps that u don't use
if there is any App that u use then just edit the Setting of that App so that it can not post on your behalf.