'$'未定义

Question

无论是否将jQuery $ .ajax调用放入,我都会收到此错误 $(document).ready(function() {.这是在ASP.NET MVC .cshtml文件中.

 <script type="text/javascript">
    $(document).ready(function() {

        $.ajax({
            url: '/api/courses',
            success: function(data) {
                var list = $('#courses');
                for (var i = 0; i < data.length; i++) {
                    var course = data[i];
                    list.append('<li id="' + course.id + '">' + course.name + '</li>');
                }
            }
        });
    });

Answer 1

确保首先引用JQuery.一些东西(使用MS CDN):

<script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.8.2.min.js" type="text/javascript"></script> 
<script type="text/javascript">
    $(document).ready(function() {
        $.ajax({
            url: '/api/courses',
            success: function(data) {
                var list = $('#courses');
                for (var i = 0; i < data.length; i++) {
                    var course = data[i];
                    list.append('<li id="' + course.id + '">' + course.name + '</li>');
                }
            }
        });
    });
</script>