2021.2.25

今日学习内容：html字符集

为了正确显示 HTML 页面，Web 浏览器必须知道要使用哪个字符集。

从 ASCII 到 UTF-8

ASCII 是第一个字符编码标准。ASCII 定义了 128 种可以在互联网上使用的字符：数字（0-9）、英文字母（A-Z）和一些特殊字符，比如：! $ + - ( ) @ < >。

ISO-8859-1 是 HTML 4 的默认字符集。此字符集支持 256 个不同的字符代码。HTML 4 同时支持 UTF-8。

ANSI（Windows-1252）是原始的 Windows 字符集。 ANSI 与 ISO-8859-1 相同，不同之处在于 ANSI 具有 32 个额外的字符。

HTML5 规范鼓励 Web 开发人员使用 UTF-8 字符集，该字符集涵盖了世界上几乎所有的字符和符号！

HTML charset 属性

为了正确显示 HTML 页面，Web 浏览器必须了解页面中使用的字符集。

这在 <meta> 标签中指定：

<meta charset="UTF-8">

字符集之间的差异

下表展示了上述字符集之间的区别：

Numb	ASCII	ANSI	8859	UTF-8	Description
32					space
33	!	!	!	!	exclamation mark
34	"	"	"	"	quotation mark
35	#	#	#	#	number sign
36	$	$	$	$	dollar sign
37	%	%	%	%	percent sign
38	&	&	&	&	ampersand
39	'	'	'	'	apostrophe
40	(	(	(	(	left parenthesis
41	)	)	)	)	right parenthesis
42	*	*	*	*	asterisk
43	+	+	+	+	plus sign
44	,	,	,	,	comma
45	-	-	-	-	hyphen-minus
46	.	.	.	.	full stop
47	/	/	/	/	solidus
48	0	0	0	0	digit zero
49	1	1	1	1	digit one
50	2	2	2	2	digit two
51	3	3	3	3	digit three
52	4	4	4	4	digit four
53	5	5	5	5	digit five
54	6	6	6	6	digit six
55	7	7	7	7	digit seven
56	8	8	8	8	digit eight
57	9	9	9	9	digit nine
58	:	:	:	:	colon
59	;	;	;	;	semicolon
60	<	<	<	<	less-than sign
61	=	=	=	=	equals sign
62	>	>	>	>	greater-than sign
63	?	?	?	?	question mark
64	@	@	@	@	commercial at
65	A	A	A	A	Latin capital letter A
66	B	B	B	B	Latin capital letter B
67	C	C	C	C	Latin capital letter C
68	D	D	D	D	Latin capital letter D
69	E	E	E	E	Latin capital letter E
70	F	F	F	F	Latin capital letter F
71	G	G	G	G	Latin capital letter G
72	H	H	H	H	Latin capital letter H
73	I	I	I	I	Latin capital letter I
74	J	J	J	J	Latin capital letter J
75	K	K	K	K	Latin capital letter K
76	L	L	L	L	Latin capital letter L
77	M	M	M	M	Latin capital letter M
78	N	N	N	N	Latin capital letter N
79	O	O	O	O	Latin capital letter O
80	P	P	P	P	Latin capital letter P
81	Q	Q	Q	Q	Latin capital letter Q
82	R	R	R	R	Latin capital letter R
83	S	S	S	S	Latin capital letter S
84	T	T	T	T	Latin capital letter T
85	U	U	U	U	Latin capital letter U
86	V	V	V	V	Latin capital letter V
87	W	W	W	W	Latin capital letter W
88	X	X	X	X	Latin capital letter X
89	Y	Y	Y	Y	Latin capital letter Y
90	Z	Z	Z	Z	Latin capital letter Z
91	[	[	[	[	left square bracket
92					reverse solidus
93	]	]	]	]	right square bracket
94	^	^	^	^	circumflex accent
95	_	_	_	_	low line
96	`	`	`	`	grave accent
97	a	a	a	a	Latin small letter a
98	b	b	b	b	Latin small letter b
99	c	c	c	c	Latin small letter c
100	d	d	d	d	Latin small letter d
101	e	e	e	e	Latin small letter e
102	f	f	f	f	Latin small letter f
103	g	g	g	g	Latin small letter g
104	h	h	h	h	Latin small letter h
105	i	i	i	i	Latin small letter i
106	j	j	j	j	Latin small letter j
107	k	k	k	k	Latin small letter k
108	l	l	l	l	Latin small letter l
109	m	m	m	m	Latin small letter m
110	n	n	n	n	Latin small letter n
111	o	o	o	o	Latin small letter o
112	p	p	p	p	Latin small letter p
113	q	q	q	q	Latin small letter q
114	r	r	r	r	Latin small letter r
115	s	s	s	s	Latin small letter s
116	t	t	t	t	Latin small letter t
117	u	u	u	u	Latin small letter u
118	v	v	v	v	Latin small letter v
119	w	w	w	w	Latin small letter w
120	x	x	x	x	Latin small letter x
121	y	y	y	y	Latin small letter y
122	z	z	z	z	Latin small letter z
123	{	{	{	{	left curly bracket
124	|	|	|	|	vertical line
125	}	}	}	}	right curly bracket
126	~	~	~	~	tilde
127	DEL
128		€			euro sign
129					NOT USED
130		‚			single low-9 quotation mark
131		ƒ			Latin small letter f with hook
132		„			double low-9 quotation mark
133		…			horizontal ellipsis
134		†			dagger
135		‡			double dagger
136		ˆ			modifier letter circumflex accent
137		‰			per mille sign
138		Š			Latin capital letter S with caron
139		‹			single left-pointing angle quotation mark
140		Œ			Latin capital ligature OE
141					NOT USED
142		Ž			Latin capital letter Z with caron
143					NOT USED
144					NOT USED
145		‘			left single quotation mark
146		’			right single quotation mark
147		“			left double quotation mark
148		”			right double quotation mark
149		•			bullet
150		–			en dash
151		—			em dash
152		˜			small tilde
153		™			trade mark sign
154		š			Latin small letter s with caron
155		›			single right-pointing angle quotation mark
156		œ			Latin small ligature oe
157					NOT USED
158		ž			Latin small letter z with caron
159		Ÿ			Latin capital letter Y with diaeresis
160					no-break space
161		¡	¡	¡	inverted exclamation mark
162		¢	¢	¢	cent sign
163		£	£	£	pound sign
164		¤	¤	¤	currency sign
165		¥	¥	¥	yen sign
166		¦	¦	¦	broken bar
167		§	§	§	section sign
168		¨	¨	¨	diaeresis
169		©	©	©	copyright sign
170		ª	ª	ª	feminine ordinal indicator
171		«	«	«	left-pointing double angle quotation mark
172		¬	¬	¬	not sign
173		­	­	­	soft hyphen
174		®	®	®	registered sign
175		¯	¯	¯	macron
176		°	°	°	degree sign
177		±	±	±	plus-minus sign
178		²	²	²	superscript two
179		³	³	³	superscript three
180		´	´	´	acute accent
181		µ	µ	µ	micro sign
182		¶	¶	¶	pilcrow sign
183		·	·	·	middle dot
184		¸	¸	¸	cedilla
185		¹	¹	¹	superscript one
186		º	º	º	masculine ordinal indicator
187		»	»	»	right-pointing double angle quotation mark
188		¼	¼	¼	vulgar fraction one quarter
189		½	½	½	vulgar fraction one half
190		¾	¾	¾	vulgar fraction three quarters
191		¿	¿	¿	inverted question mark
192		À	À	À	Latin capital letter A with grave
193		Á	Á	Á	Latin capital letter A with acute
194		Â	Â	Â	Latin capital letter A with circumflex
195		Ã	Ã	Ã	Latin capital letter A with tilde
196		Ä	Ä	Ä	Latin capital letter A with diaeresis
197		Å	Å	Å	Latin capital letter A with ring above
198		Æ	Æ	Æ	Latin capital letter AE
199		Ç	Ç	Ç	Latin capital letter C with cedilla
200		È	È	È	Latin capital letter E with grave
201		É	É	É	Latin capital letter E with acute
202		Ê	Ê	Ê	Latin capital letter E with circumflex
203		Ë	Ë	Ë	Latin capital letter E with diaeresis
204		Ì	Ì	Ì	Latin capital letter I with grave
205		Í	Í	Í	Latin capital letter I with acute
206		Î	Î	Î	Latin capital letter I with circumflex
207		Ï	Ï	Ï	Latin capital letter I with diaeresis
208		Ð	Ð	Ð	Latin capital letter Eth
209		Ñ	Ñ	Ñ	Latin capital letter N with tilde
210		Ò	Ò	Ò	Latin capital letter O with grave
211		Ó	Ó	Ó	Latin capital letter O with acute
212		Ô	Ô	Ô	Latin capital letter O with circumflex
213		Õ	Õ	Õ	Latin capital letter O with tilde
214		Ö	Ö	Ö	Latin capital letter O with diaeresis
215		×	×	×	multiplication sign
216		Ø	Ø	Ø	Latin capital letter O with stroke
217		Ù	Ù	Ù	Latin capital letter U with grave
218		Ú	Ú	Ú	Latin capital letter U with acute
219		Û	Û	Û	Latin capital letter U with circumflex
220		Ü	Ü	Ü	Latin capital letter U with diaeresis
221		Ý	Ý	Ý	Latin capital letter Y with acute
222		Þ	Þ	Þ	Latin capital letter Thorn
223		ß	ß	ß	Latin small letter sharp s
224		à	à	à	Latin small letter a with grave
225		á	á	á	Latin small letter a with acute
226		â	â	â	Latin small letter a with circumflex
227		ã	ã	ã	Latin small letter a with tilde
228		ä	ä	ä	Latin small letter a with diaeresis
229		å	å	å	Latin small letter a with ring above
230		æ	æ	æ	Latin small letter ae
231		ç	ç	ç	Latin small letter c with cedilla
232		è	è	è	Latin small letter e with grave
233		é	é	é	Latin small letter e with acute
234		ê	ê	ê	Latin small letter e with circumflex
235		ë	ë	ë	Latin small letter e with diaeresis
236		ì	ì	ì	Latin small letter i with grave
237		í	í	í	Latin small letter i with acute
238		î	î	î	Latin small letter i with circumflex
239		ï	ï	ï	Latin small letter i with diaeresis
240		ð	ð	ð	Latin small letter eth
241		ñ	ñ	ñ	Latin small letter n with tilde
242		ò	ò	ò	Latin small letter o with grave
243		ó	ó	ó	Latin small letter o with acute
244		ô	ô	ô	Latin small letter o with circumflex
245		õ	õ	õ	Latin small letter o with tilde
246		ö	ö	ö	Latin small letter o with diaeresis
247		÷	÷	÷	division sign
248		ø	ø	ø	Latin small letter o with stroke
249		ù	ù	ù	Latin small letter u with grave
250		ú	ú	ú	Latin small letter u with acute
251		û	û	û	Latin small letter with circumflex
252		ü	ü	ü	Latin small letter u with diaeresis
253		ý	ý	ý	Latin small letter y with acute
254		þ	þ	þ	Latin small letter thorn
255		ÿ	ÿ	ÿ	Latin small letter y with diaeresis

ASCII 字符集

ASCII 使用 0 到 31（以及 127）之间的值作为控制字符。

ASCII 使用 32 到 126 的值表示字母、数字和符号。

ASCII 不使用 128 到 255 之间的值。

ANSI 字符集 (Windows-1252)

对于 0 到 127 的值，ANSI 与 ASCII 相同。

ANSI 有一组专有的字符，其值从 128 到 159。

对于 160 到 255 的值，ANSI 与 UTF-8 相同。

ISO-8859-1 字符集

对于 0 到 127 的值，8859-1 与 ASCII 相同。

8859-1 不使用 128 到 159 之间的值。

对于从 160 到 255 的值，8859-1 与 UTF-8 相同。

UTF-8 字符集

对于 0 到 127 的值，UTF-8 与 ASCII 相同。

UTF-8 不使用 12 8到 159 之间的值。

对于 160 到 255 之间的值，UTF-8 与 ANSI 和 8859-1 相同。

UTF-8 从值 256 继续，包含超过 10000 个不同字符。

如需深入研究，请阅读我们完整的 HTML 字符集参考手册。

@charset CSS 规则

您可以使用 CSS @charset 规则来指定样式表中使用的字符编码：

实例

将样式表的编码设置为 Unicode UTF-8：

@charset "UTF-8";