Jquery selector, what is this $ (tagname. Class)? The form of the page is roughly as follows
Nothing can be selected. A is an indicator signature, which can be a tag name such as P or input, and this type of tag will be selected. ".XXXX" refers to all contents declared under this CSS type, and selectors will be nested in sequence. Sony, you can't choose anything in this writing, but you should also enclose it in quotation marks, otherwise you can analyze it directly according to variables.