javascript - When do I need to escape metacharectars? (jQuery Selectors) -

according jquery docs, need escape metacharacters occur in selector strings, when occur literal. however, couldn't find many specific examples of when , when not escape selectors. when , when don't need escape metacharacters, when interpreted literal, in:

attribute selectors? ie

$("[attr=value]") 

id selectors? ie

$("#id") 

class selectors? ie

$(".class"); 

and, there way write function replaces metachars in selector strings, while still preserving beginning character? ie:

// replace meta chars, preserving id selection? $("#id.rest$of*string")  // replace meta chars, preserving attribute selection? // going previous question, need escape metachars in situation? $("[attr=blah.dee#foo*yay]") 

the reason ask question, because i'm working website happens have nasty selectors. , don't have control on website, can't go change selectors nicer work with.

thanks!!

from jquery docs:

if wish use of meta-characters (#;&,.+*~':"!^$=>|/ ) as literal part of name, must escape character 2 backslashes ...

all of these must escaped:

1. id
2. class name
3. attribute name
4. attribute value
5. element name

the first 4 obvious, , here's example fifth. element names in xml can contain "." character instance , still valid.

<user.name>john doe</user.name> 

if had select elements of user.name, . must escaped

$(xml).find("user\\.name");