HTML字符实体(Character Entities)和转义字符串(Escape Sequence)


为什么要用转义字符串?

HTML中<,>,&等有特殊含义(<,>,用于链接签,&用于转义),不能直接使用。这些符号是不显示在我们最终看到的网页里的,那如果我们希望在网页中显示这些符号,该怎么办呢?

这就要说到HTML转义字符串(Escape Sequence)了。

转义字符串(Escape Sequence)也称字符实体(Character Entity)。在HTML中,定义转义字符串的原因有两个:第一个原因是像“<”和“>”这类符号已经用来表示HTML标签,因此就不能直接当作文本中的符号来使用。为了在HTML文档中使用这些符号,就需要定义它的转义字符串。当解释程序遇到这类字符串时就把它解释为真实的字符。在输入转义字符串时,要严格遵守字母大小写的规则。第二个原因是,有些字符在ASCII字符集中没有定义,因此需要使用转义字符串来表示。

转义字符串的组成

转义字符串(Escape Sequence)即字符实体(Character Entity)分成三部分:第一部分是一个&符号,英文叫ampersand;第二部分是实体(Entity)名字或者是#加上实体(Entity)编号;第三部分是一个分号。

比如,要显示小于号(<),就可以写 &lt; 或者 &#60; 。

用实体(Entity)名字的好处是比较好理解,一看lt,大概就猜出是less than的意思,但是其劣势在于并不是所有的浏览器都支持最新的Entity名字。而实体(Entity)编号,各种浏览器都能处理。

提示:实体名称(Entity)是区分大小写的。

备注:同一个符号,可以用“实体名称”和“实体编号”两种方式引用,“实体名称”的优势在于便于记忆,但不能保证所有的浏览器都能顺利识别它,而“实体编号”则没有这种担忧,但它实在不方便记忆。

如何显示空格?

通常情况下,HTML会自动截去多余的空格。不管你加多少空格,都被看做一个空格。比如你在两个字之间加了10个空格,HTML会截去9个空格,只保留一个。为了在网页中增加空格,你可以使用&nbsp;表示空格。



HTML特殊转义字符列表

最常用的字符实体
Character Entities

显示

说明

实体名称

实体编号

 

半方大的空白

&ensp;

&#8194;

 

全方大的空白

&emsp;

&#8195;

 

不断行的空白格

&nbsp;

&#160;

<

小于

&lt;

&#60;

>

大于

&gt;

&#62;

&

&符号

&amp;

&#38;

"

双引号

&quot;

&#34;

©

版权

&copy;

&#169;

®

已注册商标

&reg;

&#174;


商标(美国)


&#8482;

×

乘号

&times;

&#215;

÷

除号

&divide;

&#247;


ISO 8859-1 (Latin-1)字符集

HTML 4.01 支持 ISO 8859-1 (Latin-1) 字符集。

备注:为了方便起见,以下表格中,“实体名称”简称为“名称”,“实体编号”简称为“编号”

显示

名称

编号

显示

名称

编号

显示

名称

编号

显示

名称

编号

显示

名称

编号

 

&nbsp;

&#160;

¡

&iexcl;

&#161;

¢

&cent;

&#162;

£

&pound;

&#163;

¤

&curren;

&#164;

¥

&yen;

&#165;

¦

&brvbar;

&#166;

§

&sect;

&#167;

¨

&uml;

&#168;

©

&copy;

&#169;

ª

&ordf;

&#170;

«

&laquo;

&#171;

¬

&not;

&#172;

­

&shy;

&#173;

®

&reg;

&#174;

¯

&macr;

&#175;

°

&deg;

&#176;

±

&plusmn;

&#177;

²

&sup2;

&#178;

³

&sup3;

&#179;

´

&acute;

&#180;

µ

&micro;

&#181;


&para;

&#182;

·

&middot;

&#183;

¸

&cedil;

&#184;

¹

&sup1;

&#185;

º

&ordm;

&#186;

»

&raquo;

&#187;

¼

&frac14;

&#188;

½

&frac12;

&#189;

¾

&frac34;

&#190;

¿

&iquest;

&#191;

À

&Agrave;

&#192;

Á

&Aacute;

&#193;

Â

&Acirc;

&#194;

Ã

&Atilde;

&#195;

Ä

&Auml;

&#196;

Å

&Aring;

&#197;

Æ

&AElig;

&#198;

Ç

&Ccedil;

&#199;

È

&Egrave;

&#200;

É

&Eacute;

&#201;

Ê

&Ecirc;

&#202;

Ë

&Euml;

&#203;

Ì

&Igrave;

&#204;

Í

&Iacute;

&#205;

Î

&Icirc;

&#206;

Ï

&Iuml;

&#207;

Ð

&ETH;

&#208;

Ñ

&Ntilde;

&#209;

Ò

&Ograve;

&#210;

Ó

&Oacute;

&#211;

Ô

&Ocirc;

&#212;

Õ

&Otilde;

&#213;

Ö

&Ouml;

&#214;

×

&times;

&#215;

Ø

&Oslash;

&#216;

Ù

&Ugrave;

&#217;

Ú

&Uacute;

&#218;

Û

&Ucirc;

&#219;

Ü

&Uuml;

&#220;

Ý

&Yacute;

&#221;

Þ

&THORN;

&#222;

ß

&szlig;

&#223;

à

&agrave;

&#224;

á

&aacute;

&#225;

â

&acirc;

&#226;

ã

&atilde;

&#227;

ä

&auml;

&#228;

å

&aring;

&#229;

æ

&aelig;

&#230;

ç

&ccedil;

&#231;

è

&egrave;

&#232;

é

&eacute;

&#233;

ê

&ecirc;

&#234;

ë

&euml;

&#235;

ì

&igrave;

&#236;

í

&iacute;

&#237;

î

&icirc;

&#238;

ï

&iuml;

&#239;

ð

&eth;

&#240;

ñ

&ntilde;

&#241;

ò

&ograve;

&#242;

ó

&oacute;

&#243;

ô

&ocirc;

&#244;

õ

&otilde;

&#245;

ö

&ouml;

&#246;

÷

&divide;

&#247;

ø

&oslash;

&#248;

ù

&ugrave;

&#249;

ú

&uacute;

&#250;

û

&ucirc;

&#251;

ü

&uuml;

&#252;

ý

&yacute;

&#253;

þ

&thorn;

&#254;

ÿ

&yuml;

&#255;

数学和希腊字母标志

显示

名称

编号

显示

名称

编号

显示

名称

编号

显示

名称

编号

显示

名称

编号

ƒ

&fnof;

&#402;

Α

&Alpha;

&#913;

Β

&Beta;

&#914;

Γ

&Gamma;

&#915;

Δ

&Delta;

&#916;

Ε

&Epsilon;

&#917;

Ζ

&Zeta;

&#918;

Η

&Eta;

&#919;

Θ

&Theta;

&#920;

Ι

&Iota;

&#921;

Κ

&Kappa;

&#922;

Λ

&Lambda;

&#923;

Μ

&Mu;

&#924;

Ν

&Nu;

&#925;

Ξ

&Xi;

&#926;

Ο

&Omicron;

&#927;

Π

&Pi;

&#928;

Ρ

&Rho;

&#929;

Σ

&Sigma;

&#931;

Τ

&Tau;

&#932;

Υ

&Upsilon;

&#933;

Φ

&Phi;

&#934;

Χ

&Chi;

&#935;

Ψ

&Psi;

&#936;

Ω

&Omega;

&#937;

α

&alpha;

&#945;

β

&beta;

&#946;

γ

&gamma;

&#947;

δ

&delta;

&#948;

ε

&epsilon;

&#949;

ζ

&zeta;

&#950;

η

&eta;

&#951;

θ

&theta;

&#952;

ι

&iota;

&#953;

κ

&kappa;

&#954;

λ

&lambda;

&#955;

μ

&mu;

&#956;

ν

&nu;

&#957;

ξ

&xi;

&#958;

ο

&omicron;

&#959;

π

&pi;

&#960;

ρ

&rho;

&#961;

ς

&sigmaf;

&#962;

σ

&sigma;

&#963;

τ

&tau;

&#964;

υ

&upsilon;

&#965;

φ

&phi;

&#966;

χ

&chi;

&#967;

ψ

&psi;

&#968;

ω

&omega;

&#969;

?

&thetasym;

&#977;

?

&upsih;

&#978;

?

&piv;

&#982;


&bull;

&#8226;


&hellip;

&#8230;


&prime;

&#8242;


&Prime;

&#8243;


&oline;

&#8254;


&frasl;

&#8260;


&weierp;

&#8472;


&image;

&#8465;


&real;

&#8476;


&trade;

&#8482;


&alefsym;

&#8501;


&larr;

&#8592;


&uarr;

&#8593;


&rarr;

&#8594;


&darr;

&#8595;


&harr;

&#8596;


&crarr;

&#8629;


&lArr;

&#8656;


&uArr;

&#8657;


&rArr;

&#8658;


&dArr;

&#8659;


&hArr;

&#8660;


&forall;

&#8704;


&part;

&#8706;


&exist;

&#8707;


&empty;

&#8709;


&nabla;

&#8711;


&isin;

&#8712;


&notin;

&#8713;


&ni;

&#8715;


&prod;

&#8719;


&sum;

&#8721;


&minus;

&#8722;


&lowast;

&#8727;


&radic;

&#8730;


&prop;

&#8733;


&infin;

&#8734;


&ang;

&#8736;


&and;

&#8743;


&or;

&#8744;


&cap;

&#8745;


&cup;

&#8746;


&int;

&#8747;


&there4;

&#8756;


&sim;

&#8764;


&cong;

&#8773;


&asymp;

&#8776;


&ne;

&#8800;


&equiv;

&#8801;


&le;

&#8804;


&ge;

&#8805;


&sub;

&#8834;


&sup;

&#8835;


&nsub;

&#8836;


&sube;

&#8838;


&supe;

&#8839;


&oplus;

&#8853;


&otimes;

&#8855;


&perp;

&#8869;


&sdot;

&#8901;

?

&lceil;

&#8968;

?

&rceil;

&#8969;

?

&lfloor;

&#8970;

?

&rfloor;

&#8971;

?

&lang;

&#9001;

?

&rang;

&#9002;


&loz;

&#9674;


&spades;

&#9824;


&clubs;

&#9827;


&hearts;

&#9829;


&diams;

&#9830;

重要的国际标记
markup-significant and internationalization characters

显示

名称

编号

显示

名称

编号

显示

名称

编号

显示

名称

编号

显示

名称

编号

"

&quot;

&#34;

&

&amp;

&#38;

<

&lt;

&#60;

>

&gt;

&#62;

Œ

&OElig;

&#338;

œ

&oelig;

&#339;

Š

&Scaron;

&#352;

š

&scaron;

&#353;

Ÿ

&Yuml;

&#376;

ˆ

&circ;

&#710;

˜

&tilde;

&#732;


&ensp;

&#8194;


&emsp;

&#8195;


&thinsp;

&#8201;


&zwnj;

&#8204;


&zwj;

&#8205;


&lrm;

&#8206;


&rlm;

&#8207;


&ndash;

&#8211;


&mdash;

&#8212;


&lsquo;

&#8216;


&rsquo;

&#8217;


&sbquo;

&#8218;


&ldquo;

&#8220;


&rdquo;

&#8221;


&bdquo;

&#8222;


&dagger;

&#8224;


&Dagger;

&#8225;


&permil;

&#8240;


&lsaquo;

&#8249;


&rsaquo;

&#8250;


&euro;

&#8364;



JavaScript转义符

转义序列

字符

\b

退格

\f

走纸换页

\n

换行

\r

回车

\t

横向跳格 (Ctrl-I)

\'

单引号

\"

双引号

\\

反斜杠

编程的时候要注意特殊字符的问题,很多运行时出现的问题都是因为特殊字符的出现而引起的。

注意,由于反斜杠本身用作转义符,因此不能直接在脚本中键入一个反斜杠。如果要产生一个反斜杠,必须一起键入两个反斜杠 (\\)。