我在javascript中有排序功能，无法确定确切的位置使其正常工作

Question

下面的代码不会按字母顺序排序，其功能位于底部，我猜这是问题所在。最初，我对它进行了不同的设置，这就是为什么它起作用的原因，但我正在努力通过不同的设置来实现相同的逻辑

$.ajax({
    url: '/echo/json/',
    type: "post",
    dataType: "json",
    data: {
        json: JSON.stringify([{
                order_number: 1,
                customer: 'Jess Learmonth',
                total_cost: 200,
                processed_date: '23/01/2016'
            },

            {
                order_number: 14,
                customer: 'Adam Bowden',
                total_cost: 100,
                processed_date: '22/01/2016'
            }
        ]),

        customer_orders.sort(function(a, b) {
            return a.customer.toLowerCase().localeCompare(b.customer.toLowerCase());
        }),


        delay: 3
    },
    success: function(data, textStatus, jqXHR) {
        // since we are using jQuery, you don't need to parse response

        drawTable(data);
    }
});


function drawTable(data) {
    for (var i = 0; i < data.length; i++) {
        drawRow(data[i]);
    }
}

function drawRow(rowData) {
    var row = $("<tr />")
    $("#personDataTable").append(row); //this will append tr element to table... keep its reference for a while since we will add cels into it
    row.append($("<td>" + rowData.order_number + "</td>"));
    row.append($("<td>" + rowData.customer + "</td>"));
    row.append($("<td>" + rowData.total_cost + "</td>"));
    row.append($("<td>" + rowData.processed_date + "</td>"));
}

customer_orders.sort(function(a, b) {
    return a.customer.toLowerCase().localeCompare(b.customer.toLowerCase());
});