本讲: 29–39点(与dom相关)
29 add(params) 在$所取到的节点数组中添加新的节点．
参数可以是expr, html,element
eg: 1.<p>Hello</p><span>Hello Again</span>
$(”p”).add(”span”)==>[ <p>Hello</p>, <span>Hello Again</span> ]
2.<p>Hello</p>
$(”p”).add(”<span>Again</span>”)==>
[ <p>Hello</p>, <span>Again</span> ]3. <p>Hello</p><p><span id=”a”>Hello Again</span></p>
$(”p”).add( document.getElementById(”a”) )===>
[ <p>Hello</p>, <span id="a">Hello Again</span> ]
30 children(expr)取得子节点,当expr为空时，取得所有的子节点
eg<div><span>Hello</span><p class=”selected”>Hello Again</p><p>And Again</p></div>
$(”div”).children()==>[><span>Hello</span><p class="selected">Hello Again</p><p>And Again</p> ]
$(”div”).children(”.selected”)==>
[ <p class="selected">Hello Again</p> ]
31 contains(str)找出字节点中包含有str的节点．str起到过滤做用
eg: <p>This is just a test.</p><p>So is this</p>$("p").contains("test")==>[ <p>This is just a test.</p> ]
32. filter(expression)过滤找出符合expression的节点
eg:<p>Hello</p><p>Hello Again</p><p class="selected">And Again</p>$("p").filter(".selected")==>><p class="selected">And Again</p>$("p").filter(".selected, :first")==>[ <p>Hello</p>, <p class="selected">And Again</p> ]
filter(filter_func)通过函数来选择是否过滤，filter_func返回true表示过滤<p><ol><li>Hello</li></ol></p><p>How are you?</p>$("p").filter(function(index) { return $("ol", this).length == 0; })==>[ <p>How are you?</p> ]
33. find（expr）从子节点找出符合expr的．与filter的区别是filter过滤掉＄数组中的节点
find过滤到的是子节点eg: <p><span>Hello</span>, how are you?</p>$("p").find("span")==>[ <span>Hello</span> ];
34. is(expr) 判断是否符合条件，如果$数组的所有节点都不符合条件返回false，
只要有一个符合条件就返回trueeg: <form><p><input type="checkbox" /></p></form>$("input[@type='checkbox']").parent().is("form")==>false$("input[@type='checkbox']").parent().is("p")==>true
35 next(expr) 取得最近节点最近那个节点.expr为空时取得所有节点
eg:1.<p>Hello</p><p>Hello Again</p><div><span>And Again</span></div>$("p").next()==>[ <p>Hello Again</p>, <div><span>And Again</span></div> ]2.<p>Hello</p><p class="selected">Hello Again</p><div><span>And Again</span></div>$("p").next(".selected")==>[ <p class="selected">Hello Again</p> ]
36. not(el),not(expr),not(elems)与add相反，删除符合条件的节点．
eg:1. <p>Hello</p><p id="selected">Hello Again</p>$("p").not( $("#selected")[0] )==>[ <p>Hello</p> ]$("p").not("#selected")==>[ <p>Hello</p> ]2.<div><p>Hello</p><p class="selected">Hello Again</p></div>$("p").not( $("div p.selected") )==>[ <p>Hello</p> ]
37 parent(expr) 取得父节点
eg:1.<html><body><div><p><span>Hello</span></p><span>Hello Again</span></div></body></html>$("span").parents()==>[ <body>...</body>, <div>...</div>, <p><span>Hello</span></p> ]2.<html><body><div><p><span>Hello</span></p><span>Hello Again</span></div></body></html>$("span").parents("p")==>[ <p><span>Hello</span></p> ]
38 prev(expr) 与next相反,next取得是与节点相邻后面的．prev取得相邻前面的
eg: 1.<div><span>Hello</span></div><p class="selected">Hello Again</p><p>And Again</p>$("p").prev(".selected")==>[ <div><span>Hello</span></div> ]2.<p>Hello</p><div><span>Hello Again</span></div><p>And Again</p>$("p").prev()==>[ <div><span>Hello Again</span></div> ]
39 siblings(expr) 取得相邻两边的节点是．next,与prev的结合体
jquery与dom相关的操作先讲到这里，下回接着讲CSS相关操作
Very Good!