1 selector
1.1 Description
Selector itself is only a specific syntax rules of the string , there is no real use, it is the CSS selector syntax of its basic rules of grammar used, and the base was extended only to call $ () and select as a parameter incoming to work.
$ (Selector) effect: to find according to the selection rules in the array of the entire document, all matching tags (pseudo array), and packaged into jQuery objects returned
1.2 Classification
1) What choice is?
* String specific syntax rules (css selector)
* To find a / some DOM element: $ (selector)
2) classification
① basic
* #Id id selector
* Element (tag name) element selector
* * Arbitrary label
* .Class attribute selectors
* Selector1, selector2, selector3 take the union of a plurality of selectors (selectors composition)
* Selector1selector2selector3 intersection take a plurality of selectors (selector intersect)
② level
* Find a child element, selectors descendant elements, of siblings
* Selector1> selector2 (parent> child): the sub-element, the matching elements in a given sub-element of the parent element
* Selector1 selector2 (ancestor descendant): offspring element, the element matching element in the offspring at a given ancestor element
* Selector1 + selector2 (prev + next): Immediately after the match all elements prev next element. uncommonly used
* Selector1 ~ selector2 (prev ~ siblings): matching prev (front) of all siblings (brothers and sisters) after the element element. uncommonly used
③ filter
* Matching elements in the original filter out some of the (divided into basic, content, visibility, three properties)
* :first
* :last
* :eq(index)
* :lt
* :gt
* :odd
* :even
* :not(selector)
* :hidden
* :visible
* [attrName]
* [attrName=value]
④ Form
* :input
* :text
* :checkbox
* :radio
*: Checked: Selected
Basic Selector:
<body>
<div id="div1" class="box">div1(class="box")</div>
<div id="div2" class="box">div2(class="box")</div>
<div id="div3">div3</div>
<span class="box">span(class="box")</span>
<br>
<ul>
<
<>> AAAAA </as
title="hello">BBBBB(title="hello")</li>
<li class="box">CCCCC(class="box")</li>
<li title="hello">DDDDDD(title="hello")</li>
</ul> <script src="js/jquery-1.10.1.js" type="text/javascript"></script>
<script type="text/javascript">
// 1. Select id as div1 elements
$ ( '# div1' ) .css ( 'background' , 'Red' )
// 2. Select all of the elements div
$ ( 'div' ) .css ( 'background' , 'Red' )
//. 3. select all class attribute box element
$ ( '.box' ) .css ( 'background' , 'Red' )
//. 4. select all div and span elements
$ ( ' div , span ' ) .css ( ' background ' , ' Red ' )
//. 5.Select all the class attribute box div element
$('div.box').css('background', 'red')
$('*').css('background', 'red') </script> </body> |
Level selector:
<body>
<ul>
<li>AAAAA</li>
<li class="box">CCCCC</li>
<li title="hello"><span>BBBBB</span></li>
<li title="hello"><span class="box">DDDD</span></li>
<span>EEEEE</span>
</ul>
<script src="js/jquery-1.10.1.js" type="text/javascript"></script>
<script type="text/javascript">
//1. 选中ul下所有的的span
$('ul span').css('background', 'yellow')
//2. 选中ul下所有的子元素span
$('ul>span').css('background', 'yellow')
//3. 选中class为box的下一个li
$('.box+li').css('background', 'yellow')
//4. 选中ul下的class为box的元素后面的所有兄弟元素
$('ul .box~*').css('background', 'yellow')
</script> </body> |
过滤选择器：
<body>
<div id="div1" class="box">class为box的div1</div>
<div id="div2" class="box">class为box的div2</div>
<div id="div3">div3</div>
<span class="box">class为box的span</span>
<br/>
<ul>
<li>AAAAA</li>
<li title="hello">BBBBB</li>
<li class="box">CCCCC</li>
<li title="hello">DDDDDD</li>
<li title="two">BBBBB</li>
<li style="display:none">我本来是隐藏的</li>
</ul>
<script src="js/jquery-1.10.1.js" type="text/javascript"></script>
<script type="text/javascript"> //1. 选择第一个div
$('div:first').css('background', 'red')
//2. 选择最后一个class为box的元素
$('.box:last').css('background', 'red')
//3. 选择所有class属性不为box的div
$('div:not(.box)').css('background', 'red') //没有class属性也可以
//4. 选择第二个和第三个li元素
//$('li:gt(0):lt(3)').css('background', 'red') // 多个过滤选择器不是同时执行, 而是依次
$('li:gt(0):lt(2)').css('background', 'red') // 多个过滤选择器不是同时执行, 而是依次
$('li:lt(3):gt(0)').css('background', 'red')
//5. 选择内容为BBBBB的li
$('li:contains("BBBBB")').css('background', 'red')
//6. 选择隐藏的li
console.log($('li:hidden').length, $('li:hidden')[0])
//7. 选择有title属性的li元素
$('li[title]').css('background', 'red')
//8. 选择所有属性title为hello的li元素
$('li[title="hello"]').css('background', 'red')
</script>
</body> |
表单选择器：
<body>
<form>
用户名: <input type="text"/><br>
密 码: <input type="password"/><br>
爱 好:
<input type="checkbox" checked="checked"/>篮球
<input type="checkbox"/>足球
<input type="checkbox" checked="checked"/>羽毛球 <br>
性 别:
<input type="radio" name="sex" value='male'/>男
<input type="radio" name="sex" value='female'/>女<br>
邮 箱: <input type="text" name="email" disabled="disabled"/><br>
所在地:
<select>
<option value="1">北京</option>
<option value="2" selected="selected">天津</option>
<option value="3">河北</option>
</select><br>
<input type="submit" value="提交"/>
</form>
<script src="js/jquery-1.10.1.js" type="text/javascript"></script>
<script type="text/javascript">
//1. 选择不可用的文本输入框
$(':text:disabled').css('background', 'red')
//2. 显示选择爱好 的个数
console.log($(':checkbox:checked').length)
//3. 显示选择的城市名称
$(':submit').click(function () {
var city = $('select>option:selected').html() // 选择的option的标签体文本
city = $('select').val() // 选择的option的value属性值
alert(city)
})
</script>
</body> |
2工具
$.each(): 遍历数组或对象中的数据
$.trim(): 去除字符串两边的空格
$.type(obj): 得到数据的类型
$.isArray(obj): 判断是否是数组
$.isFunction(obj): 判断是否是函数
$.parseJSON(json) : 解析json字符串转换为js对象/数组
···
<script src="js/jquery-1.10.1.js" type="text/javascript"></script>
<script type="text/javascript">
//1. $.each(): 遍历数组或对象中的数据
var obj = {
name: 'Tom',
setName: function (name) {
this.name = name
}
}
$.each(obj, function (key, value) {
console.log(key, value)
})
//2. $.trim(): 去除字符串两边的空格
//3. $.type(obj): 得到数据的类型
console.log($.type($)) // 'function'
//4. $.isArray(obj): 判断是否是数组
console.log($.isArray($('body')), $.isArray([])) // false true
//5. $.isFunction(obj): 判断是否是函数
console.log($.isFunction($)) // true
//6. $.parseJSON(json) : 解析json字符串转换为js对象/数组
var json = '{"name":"Tom", "age":12}' // json对象: {}
// json对象===>JS对象
console.log($.parseJSON(json))
json = '[{"name":"Tom", "age":12}, {"name":"JACK", "age":13}]' // json数组: []
// json数组===>JS数组
console.log($.parseJSON(json))
/*
JSON.parse(jsonString) json字符串--->js对象/数组
JSON.stringify(jsObj/jsArr) js对象/数组--->json字符串
*/
</script> |