ie不识别jquery的data吗

    $('.slide').each(function(i){
    
}).on("mousewheel", function(){
    var e=window.event||event||e;
    var dir=e.wheelDelta||e.detail;
    var _=$(this);
    console.log(dir);
    jump(dir,_);
})
function jump(dir,_){
    if(dir==-120||dir==-3){
        item=parseInt(_.data("index"));
        if(item<slideLength-1){
        var x=-parseInt(item+1)+"00%";
        $(".slide").css({transition:"transform 1s ease",transform:"translate3d(0,"+x+",0)"});
        }
    }else{
        item=parseInt(_.data("index"));
        if(item>0){
        var y=-parseInt(item-1)+"00%";
        $(".slide").css({transition:"transform 1s ease",transform:"translate3d(0,"+y+",0)"});
        }
    }
}

这个为什么在ie下不可以运行呢，我console.log(item),得到的不是1，2，3是function item() { [native code]}