动态字符串中的Javascript切片字符

Question

I am trying the remove the last four characters of each dropdown item in a dynamic file list.

I have tried to use javascript spice syntax after reading this thread , but it seems to remove the full string of the other item in the list rather than just characters. list = list.slice(0, -1);

I'm not sure what is wrong with my approach.

function load_list() {
            $("#filename").empty();
            $.ajax({
                type: 'GET',
                dataType: 'json',
                url: "/cgi-bin/list_cgi?action=get_list",
                success: function(result) {
                    var list = result.file.sort();
                    var current = result.current.split("/").pop();
                    list = list.slice(0, -1);
                    if (list.length == 0) {
                        $("#unavailable").html("<h2>File not found, please upload.</h2>");
                        show_upload();
                        return;
                    }
                    for (var i in list) {
                        $("filename").append("<option>" + list[i] + "</option>");
                                            }
                    $("filename").val(current);


                }
            });
        }

Answer 1

try this

    $.each(list,function(i){
  list[i].slice(0, -4);
});

assuming you have sorted files into list object ..

or just replace your code

for (var i in list) {
                    $("filename").append("<option>" + list[i] + "</option>");
                                        }

with

$.each(list, function(i){
list[i] = list[i].slice(0,-4);
$("filename").append("<option>" + list[i] + "</option>");
})

Answer 2

You are slicing an Array and not a string.

Try to use slice in this loop instead.

for (var i in list) {
                        list[i] = list[i].slice(0, -4); //remove last 4 characters
                        $("filename").append("<option>" + list[i] + "</option>");
              }

Update: answering the comment,

You can use

for (...) {
        // use value attribute to ensure that the value is used in its entirety.
        $("filename").append("<option value='" + list[i] + "'>" + list[i].slice(0, -4) + "</option>");
}