Javascript - 截取字符串

str.split("xxx")

<input type="hidden" value='' id="bgimgid">
<script>
    var str = '/app/upload/image/survey/bg476.jpg';
    var arr = new Array();
    arr = str.split("/");
    if(arr.length > 1){
        var result = arr[arr.length-2];
        document.getElementById("bgimgid").value = result;
    }
</script>