Html Escape characters

This article is published in sync with the tiankonguse blog

Today I encountered the problem of html character escaping, So I recorded it.

Problem Reproduction

You can add a title field to the link to describe the link.

However, the characters in this title are strictly restricted and cannot contain characters such as quotation marks or spaces. Therefore, I need to escape the characters.

This title is automatically generated using php in the background, so you need to use php to escape the string.

Solution

Php has a string replacement function str_replace which is very convenient.

Let's take a look at my character escape code.

$_title = str_replace( array("\""," ","<",">","&"), array("""," ","<",">","&"),$title);

This line of code can escape some characters.

The first parameter indicates the search character, the second parameter indicates the replacement character, and the third parameter indicates the original string.

HTML character extension knowledge

The Escape string (Escape Sequence) is also called the Character Entity ).

In HTML, there are two reasons for defining escape strings: The first reason is that symbols such as "<" and ">" are already used to represent HTML tags, therefore, it cannot be used directly as a symbol in the text. To use these symbols in HTML documents, you need to define its escape string. When the interpreter encounters such a string, it is interpreted as a real character. When you enter an escape string, you must strictly follow the uppercase/lowercase rules. The second reason is that some characters are not defined in the ASCII character set, so escape strings must be used for representation.

Composition of escape strings

The Character Entity is divided into three parts: The first part is an & symbol, which is called ampersand; the second part is an Entity) name or # With the Entity number; the third part is a semicolon.

For example, to display a smaller sign (<), you can write & lt; or & #60 ;.

List of special HTML Escape characters

Display	Description	Entity name	Entity ID
	Blank	& Ensp;	& #8194;
	Wide white space	& Amp; emsp;	& #8195;
	Blank rows	& Nbsp;	& #160;
<	Less	& Lt;	& #60;
>	Greater	& Gt;	& #62;
&	& Symbol	& Amp;	& #38;
"	Double quotation marks	& Quot;	& Amp; #34;
?	Copyright	& Copy;	& #169;
?	Registered Trademark	& Reg;	& #174;
?	Trademark (USA)	?	& #8482;
×	Multiplication number	& Times;	& #215;
Bytes	Division Number	& Divide;	& #247;

JavaScript Escape Character

Escape Sequence	Character
\ B	Return
\ F	Take the form of paper
\ N	Line feed
\ R	Enter
\ T	Horizontal hop (Ctrl-I)
\'	Single quotes
\"	Double quotation marks
\\	Backslash

References

Http://114.xixik.com/character/