Could you please check what is the difference between both the snippet?

Dear Member,

Could you please check what is the difference between both the snippet? 

First one is giving wrong output.

Sumit

                parentPage = (prevPageItem && prevPageItem.parentPage.documentOffset >= element.getParentPage().documentOffset) ?
                    prevPageItem.parentPage :
                    (element.getParentPage().documentOffset > firstPage.documentOffset) ?
                        element.getParentPage() :
                        document.pages.item(parentPage.documentOffset + 1);

parentPage = (function () {
                    if (prevPageItem && prevPageItem.parentPage.documentOffset >= element.getParentPage().documentOffset)
                        return prevPageItem.parentPage;
                    else if ((elementParentPage = element.getParentPage()).documentOffset > firstPage.documentOffset)
                        return elementParentPage;
                    else return document.pages.item(firstPage.documentOffset + 1);
                }).call();

VS