Stack　Overflow　(SO)　is　one　of　the　world’s　largest　technical　Q&A　websites,　in　which　many　posts　contain　code　snippets.　However,　these　code　snippets　may　not　comply　with　coding　style　guidelines　and　result　in　the　problem　of　low　readability　and　maintainability.　To　provide　a　better　understanding　of　this　coding　style　compliance　issue　for　SO　users,　we　plan　and　conduct　an　empirical　study　on　SO.　Specifically,　we　collected　over　400,000　code　snippets　from　SO　in　three　languages,　namely　Python,　C/C++,　and　JavaScript.　The　posts　are　divided　into　two　types　(i.e.,　question　and　answer)　and　analyzed　separately.　We　found　that　for　the　question-　and　answer-type　posts,　more　than　90%　and　60%　of　code　snippets　contain　style　violations.　The　most　frequently　found　violation　is　syntax　errors　for　Python　and　indentations　for　C/C++　and　JavaScript.　In　addition,　the　results　show　that　with　more　violations　in　code　snippets,　the　＇Score＇　of　Python　and　C/C++　posts,　the　＇FavoriteCount＇　of　C/C++　questions,　and　the　＇CommentCount＇　of　JavaScript　questions　tend　to　be　lower.　The　findings　of　our　research　indicate　that　code　snippets　on　SO　do　not　have　good　coding　style　compliance.　Users,　especially　programming　beginners　are　supposed　to　be　wary　of　the　potential　problems　of　reusing　code　snippets　on　SO.　©　2023　Knowledge　Systems　Institute　Graduate　School.　All　rights　reserved.