DOM元素Javascript

Question

我有附件

cardBodyButton.addEventListener('click', function(){
    listGroup.append(addTodo());
})

而且我有一个功能

var addTodo = function(){
    var todoList = document.createElement('li');

    todoList.className = "list-group-item d-flex justify-content-between";
    todoList.appendChild(document.createTextNode('Todo 5'));

    var todoList_a = document.createElement('a');
    todoList_a.className = "delete-item";
    todoList_a.setAttribute('href','#');

    var todoList_a_i = document.createElement('i');
    todoList_a_i.className = "fa fa-remove";

    todoList_a.append(todoList_a_i);

    todoList.append(todoList_a);  
};

我正在尝试在append中调用函数，但是它说undefined。这里出了什么问题？

Answer 1

我忘了在函数内返回值