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JavaScript

Posted by Chris Feltus
Chris Feltus
3,970 Points

Syntax Error: Cannot read property 'children' of null

Having an issue with a syntax error I can't seem to figure out working through the build a to-do app in javascript. The error reports "Cannot read property 'children' of null".

Here is the code

var taskInput = document.getElementById('new-task');
var addButton = document.getElementsByTagName('button')[0];
var incompleteTasksHolder = document.getElementById('incomplete-tasks'); //ul #incomplete-tasks
var completedTasksHolder = document.getElementById('complete-tasks'); 

//event handlers
var addTask = function () {
  console.log('add task...');
}

var editTask = function () {
  console.log('edit task...');
}

var deleteTask = function() {
  console.log('delete task...');
}

var taskCompleted = function () {
  console.log('task completed...');
}

var taskIncomplete = function () {
  console.log('task incomplete');
}

var bindTaskEvents = function(taskListItem, checkBoxEventHandler) {
  console.log('bind list item events');

}

for (var i = 0; i < incompleteTasksHolder.children.length; i++) {
  bindTaskEvents(incompleteTasksHolder.children[i], taskCompleted);
}

for (var i = 0; i < completedTasksHolder.children.length; i++) {
  bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);
}

The error is pointing to this line specifically

for (var i = 0; i < completedTasksHolder.children.length; i++) {

Not sure why the syntax error is reporting the children is null. It contains items. As shown here in the html

  <ul id="completed-tasks">
        <li>
          <input type="checkbox" checked>
          <label>See the Doctor</label>
          <input type="text">
          <button class="edit">Edit</button>
          <button class="delete">Delete</button>
        </li>
      </ul>
    </div><!--completed tasks-->

1 Answer

Chris Feltus
Chris Feltus
3,970 Points

Pretty stupid mistake, just noticed I left of a d: complete*d*-tasks