Js杂记-1
1、compareDocumentPosition返回值
【父】【子】【前】【后】【非同一文档】
匹配为1，反之为0。相等是00000

var contains = document.compareDocumentPosition ? function(a, b){return !!(a.compareDocumentPosition(b) & 16);} : function(a, b){return a !== b && (a.contains ? a.contains(b) : true);};

2、nodeType
1-ELEMENT
2-ATTRIBUTE
3-TEXT
4-CDATA
5-ENTITY REFERENCE
6-ENTITY
7-PI (processing instruction)
8-COMMENT
9-DOCUMENT
10-DOCUMENT TYPE
11-DOCUMENT FRAGMENT
12-NOTATION

3、最近看jquery的sizzle

var chunker = /((?:\((?:\([^()]+\)|[^()]+)+\)|\[(?:\[[^[\]]*\]|['"][^'"]*['"]|[^[\]'"]+)+\]|\\.|[^ >+~,(\[\\]+)+|[>+~])(\s*,\s*)?((?:.|\r|\n)*)/g,

拆分第一步

((?:\((?:\([^()]+\)|[^()]+)+\)|\[(?:\[[^[\]]*\]|['"][^'"]*['"]|[^[\]'"]+)+\]|\\.|[^ >+~,(\[\\]+)+|[>+~])(\s*,\s*)?((?:.|\r|\n)*)

再细分一下最长的

((?:\((?:\([^()]+\)|[^()]+)+\)|\[(?:\[[^[\]]*\]|['"][^'"]*['"]|[^[\]'"]+)+\]|\\.|[^ >+~,(\[\\]+)+|[>+~])