Question

https://pandas.pydata.org/pandas-docs/stable/user_guide/groupby.html#enumerate-groups我需要修改displaySortedTaskList函数，以便在传递了3个参数的情况下运行该函数，并且在没有传递3个参数的情况下，抛出带有错误消息的错误对象。我的尝试：

           "use strict";
            var sortTaskList = function(tasks) {
                var isArray = Array.isArray(tasks);
                if (isArray) {
                    tasks.sort();
                }
                return isArray;
            };

            var displaySortedTaskList = function(tasks, div, handler) {
                if(arguments.length = Function.length){

                var html = "";
                var isArray = sortTaskList(tasks);

                        if (isArray) {
                    //create and load html string from sorted array
                    for (var i in tasks) {
                        html = html.concat("<p>");
                        html = html.concat("<a href='#' id='", i, "'>Delete</a>");
                        html = html.concat(tasks[i]);
                        html = html.concat("</p>");
                    }
                    div.innerHTML = html;

                    // get links, loop and add onclick event handler
                    var links = div.getElementsByTagName("a");
                    for (var i = 0; i < links.length; i++) {
                        links[i].onclick = handler;
                        } 
                    }
                } else {document.getElementById("message").innerHTML = "The displaySortedTaskList function of the tasklist library requires three arguments"}
            };

            var deleteTask = function(tasks, i) {  
                var isArray = sortTaskList(tasks);
                if (isArray) { tasks.splice(i, 1); }
            };

            var capitalizeTask = function(task) {
                var first = task.substring(0,1);
                return first.toUpperCase() + task.substring(1);
            };

Answer 1

您可以使用rest参数并检查数组的长度是否为3：

undefined

（请注意，插入文本时应分配给savedBill-在插入HTML标记时使用id是适当的，

实时摘要：

      let expectedBill = new Bill({
        type: "Test Type",
        dueDate: "2018-03-13T06:00:00.000Z", // change date to standardized format
        company: "Test Company",
        amtDue: "100",
        paidStatus: "Test Status"
      });      

      expectedBill.save(function(err, savedBill) {
        const id = savedBill._id; // store id, it is always returned as _id

        chai.request(server)
          .get('/api/bills/'+id)
          .end((err, res) => {
            // ...
            done();
          });
      });

arguments.length如果传递了3个参数，则运行该函数，否则抛出错误对象

1 个答案: