Third, jquery selector

Attention:

jquery gets the object forever, even if the element is not on the page

Cannot judge if ($ (' #tt ')) {}

The IF ($ (' #tt ') should be judged based on the length of the element. Length > 0) {}

or convert to Dom to determine if ($ (' #tt ') [0]) {}

First, the basic selector

The basic selector is the most commonly used selector in jquery and is the simplest selector for finding DOM elements through element Id,class, tag names, and so on.

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/37/C8/wKiom1Ov4wzTaKNhAAFZs1AjZjo953.jpg "title=" 23411234.JPG "alt=" Wkiom1ov4wztaknhaafzs1ajzjo953.jpg "/>

Second, level selector

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/37/C8/wKiom1Ov4w2S_bG6AAIV7RB4Ft0451.jpg "title=" 325453453.JPG "alt=" Wkiom1ov4w2s_bg6aaiv7rb4ft0451.jpg "/>

Third, filter selector

1. Basic Filter Selector

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M00/37/C7/wKioL1Ov4t-hvwF3AAVOHFdzM0Q176.jpg "title=" 234234234.png "alt=" Wkiol1ov4t-hvwf3aavohfdzm0q176.jpg "/>

2. Content Filter Selector

650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M01/37/C8/wKiom1Ov4w7zb9SnAAFRsJuhpJU468.jpg "title=" content filtering. JPG "alt=" Wkiom1ov4w7zb9snaafrsjuhpju468.jpg "/>

3. Visibility Filter Selector

650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M02/37/C7/wKioL1Ov4t-QoOrHAADvVrvLYmk979.jpg "title=" visibility filtering. JPG "alt=" Wkiol1ov4t-qoorhaadvvrvlymk979.jpg "/>

4. Attribute Filter Selector

650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M00/37/C7/wKioL1Ov4uDCpR4PAAJfIf-62Rg750.jpg "title=" attribute filtering. JPG "alt=" Wkiol1ov4udcpr4paajfif-62rg750.jpg "/>

5, sub-element filter Selector

650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/37/C7/wKioL1Ov5OixLbAtAAYHRKxF9zk126.jpg "title=" Untitled. png "alt=" wkiol1ov5oixlbataayhrkxf9zk126.jpg "/>

6. Form object Property Filter Selector

650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M00/37/C8/wKiom1Ov4w7QK8CbAAFSR7MfyhY311.jpg "title=" form elements. JPG "alt=" Wkiom1ov4w7qk8cbaafsr7mfyhy311.jpg "/>

Four, form selector

650) this.width=650, "src=" http://s3.51cto.com/wyfs02/M01/37/C7/wKioL1Ov4t-A_KQpAAJapdcODaU844.jpg "title=" form selection. JPG "alt=" Wkiol1ov4t-a_kqpaajapdcodau844.jpg "/>

Five, attention to special symbol processing

<div id= "id#b" >bb</div>

<div id= "Id[1" >cc</div>

$ (' #id #b ')

$ (' #id [1] ') cannot be obtained

To escape

$ (' #id \ #b ')

$ (' #id \\[1\\] ')