JAVASCRIPT基础学习篇（10）附2－URL编码转换,escape() encodeURI() encodeURIComponent()

1. escape()方法：
2. 采用ISOLatin字符集对指定的字符串进行编码。所有的空格符、标点符号、特殊字符以及其他非ASCII字符都将被转化成%xx格式的字符编码（xx等于该字符在字符集表里面的编码的16进制数字）。比如，空格符对应的编码是%20。unescape方法与此相反。不会被此方法编码的字符：@*/+
3. 英文解释：MSDNJScriptReference:Theescapemethodreturnsastringvalue(inUnicodeformat)thatcontainsthecontentsof[theargument].Allspaces,punctuation,accentedcharacters,andanyothernon-ASCIIcharactersarereplacedwith%xxencoding,wherexxisequivalenttothehexadecimalnumberrepresentingthecharacter.Forexample,aspaceisreturnedas"%20."
4. EdgeCoreJavascriptGuide:Theescapeandunescapefunctionsletyouencodeanddecodestrings.TheescapefunctionreturnsthehexadecimalencodingofanargumentintheISOLatincharacterset.TheunescapefunctionreturnstheASCIIstringforthespecifiedhexadecimalencodingvalue.
5. encodeURI()方法：把URI字符串采用UTF-8编码格式转化成escape格式的字符串。不会被此方法编码的字符：!@#$&*()=:/;?+'
6. 英文解释：MSDNJScriptReference:TheencodeURImethodreturnsanencodedURI.IfyoupasstheresulttodecodeURI,theoriginalstringisreturned.TheencodeURImethoddoesnotencodethefollowingcharacters:":","/",";",and"?".UseencodeURIComponenttoencodethesecharacters.EdgeCoreJavascriptGuide:EncodesaUniformResourceIdentifier(URI)byreplacingeachinstanceofcertaincharactersbyone,two,orthreeescapesequencesrepresentingtheUTF-8encodingofthecharacter
7. encodeURIComponent()方法：把URI字符串采用UTF-8编码格式转化成escape格式的字符串。与encodeURI()相比，这个方法将对更多的字符进行编码，比如/等字符。所以如果字符串里面包含了URI的几个部分的话，不能用这个方法来进行编码，否则/字符被编码之后URL将显示错误。不会被此方法编码的字符：!*()
8. 英文解释：MSDNJScriptReference:TheencodeURIComponentmethodreturnsanencodedURI.IfyoupasstheresulttodecodeURIComponent,theoriginalstringisreturned.BecausetheencodeURIComponentmethodencodesallcharacters,becarefulifthestringrepresentsapathsuchas/folder1/folder2/default.html.Theslashcharacterswillbeencodedandwillnotbevalidifsentasarequesttoawebserver.UsetheencodeURImethodifthestringcontainsmorethanasingleURIcomponent.MozillaDeveloperCoreJavascriptGuide：EncodesaUniformResourceIdentifier(URI)componentbyreplacingeachinstanceofcertaincharactersbyone,two,orthreeescapesequencesrepresentingtheUTF-8encodingofthecharacter.
9. 引用内容
10. 因此，对于中文字符串来说，如果不希望把字符串编码格式转化成UTF-8格式的（比如原页面和目标页面的charset是一致的时候），只需要使用escape。如果你的页面是GB2312或者其他的编码，而接受参数的页面是UTF-8编码的，就要采用encodeURI或者encodeURIComponent。
11. 另外，encodeURI/encodeURIComponent是在javascript1.5之后引进的，escape则在javascript1.0版本就有。
12. 英文注释：Theescape()methoddoesnotencodethe+characterwhichisinterpretedasaspaceontheserversideaswellasgeneratedbyformswithspacesintheirfields.Duetothisshortcoming,youshouldavoiduseofescape()wheneverpossible.ThebestalternativeisusuallyencodeURIComponent().UseoftheencodeURI()methodisabitmorespecializedthanescape()inthatitencodesforURIs[REF]asopposedtothequerystring,whichispartofaURL.UsethismethodwhenyouneedtoencodeastringtobeusedforanyresourcethatusesURIsandneedscertaincharacterstoremainun-encoded.Notethatthismethoddoesnotencodethe'character,asitisavalidcharacterwithinURIs.Lastly,theencodeURIComponent()methodshouldbeusedinmostcaseswhenencodingasinglecomponentofaURI.ThismethodwillencodecertaincharsthatwouldnormallyberecognizedasspecialcharsforURIssothatmanycomponentsmaybeincluded.Notethatthismethoddoesnotencodethe'character,asitisavalidcharacterwithinURIs.