LocalStoring an array on Intel XDK

if(window.localStorage.getItem("_cevaplar")!==undefined
                   || window.localStorage.getItem("_sorular")!==undefined){
                    cevaplar = JSON.parse(window.localStorage.getItem("_cevaplar"));
                    sorular = JSON.parse(window.localStorage.getItem("_sorular"));
                }

When I use this code, it returns the default value. I also checked Intel's documentation, but there is no other information about array storing. Any idea?