jQuery源码分析(6) - $.xxx()和$().xxx()幕后

<script src="jquery-1.9.1.min.js"></script>
<script>
$.extend({
  leftTrim:function (str) {
    return str.replace(/^\s+/,‘‘);
  }
});
</script>
<script>
$(function () {
  var str = ‘ hello ‘;
  alert(‘(‘+$.leftTrim(str)+‘)‘);
});
</script>

<script src="jquery-1.9.1.min.js"></script>
<script>
$.fn.extend({
  drag:function () {
  var disX = 0;
  var disY = 0;
  var This = this;
  this.mousedown(function (ev) {
    disX = ev.pageX - $(this).offset().left;
    disY = ev.pageY - $(this).offset().top;
    $(document).mousemove(function (ev) {
      This.css(‘left‘,ev.pageX-disX);
      This.css(‘top‘,ev.pageY-disY);
    });
    $(document).mouseup(function () {
      $(this).off();
    });
    return false;
  });
 }
});
</script>
<script>
$(function () {
  $(‘div‘).drag();
});
</script>