Differences between jquery single quotes and double quotes and usage notes

Executable Syntax: $ ("ul li "). filter (": contains ('canon '),: contains ('panasonic'),: contains ('case')" ).css ("color", "red ");

Incorrect syntax: $ ("ul li "). filter (": contains (" canon "),: contains (" Panasonic "),: contains (" Casio ")" ).css ("color", "red ");

According to the data, single quotes and double quotation marks are the same in Javascript, but the problem is encountered. Baidu gave me the answer, saying that single quotes should be used whenever possible, two quotation marks are used at the same time only when Nesting is encountered. That is to say, double quotation marks must be used when the outside is single quotation marks, and single quotation marks must be used when the outside is double quotation marks. In short, double quotation marks or single quotation marks cannot be used at the same time;