ESCAPE General
In coding, "escape" refers to a way to include special characters in a string that would
otherwise be difficult or impossible to include. These special characters may include things
like quotation marks, backslashes, or newline characters.
When you want to include a special character in a string, you can use an escape sequence,
which typically starts with a backslash (\) followed by a specific character. For example,
if you want to include a double quote within a string that is also enclosed in double
quotes, you would need to "escape" the inner double quote to differentiate it from the outer
quotes.
Escaping ensures that special characters are interpreted literally as part of the string
value rather than their JSON,JS or etc specific functions.
By using escape sequences, you can include special characters in your strings without
causing syntax errors, parsing errors or unintended behavior in your code.
Here's a list of characters that typically need escaping in JSON,JS etc strings when including HTML content:
NOTE: Escape characters in this part are a gathering collection. Some is used in some languages, some not. Check the related parts down in this page to get the proper results.
\): Escape it as \\ to represent a
literal backslash. Print a real backslash If you need a real backslash then you need to
escape the back slash. The computer will only print one backslash."): Escape it as \" to include
double quotes within a JSON etc string. In some cases a double quote has a special
meaning, and should be escaped if you really want a double quote.'): While less common in HTML, escape it as
\' if used.
\n): Escape it as \n to represent a
line break. Adds a newline at that place in the text (similar to pressing Enter). It
might be show n with the ¶ in your translation program.\t): Escape it as \t to represent a
horizontal tab. Add a tab marker at that spot in the text. This is sometimes used to
align text in columns.\r): Escape it as \r to
represent a carriage return. Return without advancing the line This is usually used with
n in software for Windows.\b): Escape it as \b to represent
a backspace.\f): Escape it as \f to represent
a form feed./): While not strictly required, escaping
it as \/ can sometimes be helpful to avoid confusion with JSON etc path
separators.\v): Seldom used in modern JavaScript,
inserts a vertical tab character.\ followed by three octal digits) and Hexadecimal (\x
followed by two hexadecimal digits) Escapes:: Advanced
Escapes: These allow representing characters using their octal or
hexadecimal codes, useful for uncommon characters. Not commonly used in everyday
JavaScript.<): <": This represents the less than
sign (<).>): ">": This represents the greater
than sign (>).&):1. Backslash (\)
"This string includes a backslash \\ for a
specific purpose."
2. Double Quote (")
"He said, \"This is a quote within a
quote\"."
3. Single Quote (')
'This isn't the
most common use case, but you can escape a single
quote if needed: \'example\'.' (Less common in HTML)
4. Newline (\n)
"This JSON string includes a newline \n for
readability."
5. Tab (\t)
"This JSON string has a \ttab character for
formatting."
6. Carriage Return (\r)
This is less common in modern HTML, but for completeness:
"This JSON string has a \rcarriage return for
compatibility with older systems."
7. Backspace (\b)
"This JSON string uses a \bbackspace to correct
a typo (may not be visually apparent)."
8. Form Feed (\f)
This is rarely used in modern HTML, but for completeness:
"This JSON string has a \fform feed for
compatibility with legacy systems."
9. Forward Slash (/)
"The path to my file is
/user/documents\/important_file.txt" (Escaping here improves readability, but not strictly necessary)
While escaping characters in JavaScript serves a similar purpose as in JSON, there are some contextual differences. Here are examples of escape character usage in JavaScript:
1. Backslash (\)
let longString = "This is
a very long string that \
continues on the next line.";
2. Single Quote (')
let message = 'He said,
"Isn\'t this cool?"';
3. Double Quote (")
let filename = "user's_data.txt";
4. Newline (\n)
let message = "Line
1\nLine 2";
console.log(message); //
Outputs: Line 1
// Line 2
5. Tab (\t)
let code = "function\tdoSomething() {\n\t// Code
here\n}";
console.log(code); //
Displays the code with proper indentation (may vary depending on console)
6. Carriage Return (\r)
let message = "Line
1\rLine 2"; //
Not recommended for modern use
7. Backspace (\b)
let text = "This is
a test\b!";
console.log(text); //
Output might vary depending on console, may not show a visible change
8. Form Feed (\f)
9. Vertical Tab (\v)
10. Octal (\ followed by three octal digits) and Hexadecimal (\x
followed by two hexadecimal digits) Escapes:
Remember:
Escape characters are not always necessary in XML or XHTML, but they can be used in certain situations to ensure proper parsing and interpretation of the data. Here's a breakdown of when they might be helpful:
Scenarios Where Escape Characters Are Useful:
Special Characters Within Attribute Values:
<,
>, &, ', or " within
an attribute value, you should escape them using character references. This
prevents the parser from mistaking them for XML markup.
<span title="He said, "Hello!"">
(represents a span element with a title containing a double quote)CDATA Sections:
<description><![CDATA[This text contains
<tags> and & special characters, but they won't be parsed
as XML.]]></description>
Scenarios Where Escape Characters Are Not Needed:
Key Points:
In summary: While escape characters aren't mandatory for all content in XML/XHTML, they become important when dealing with special characters within attribute values or including large sections of raw text.
1. Less Than (<)
<img src="<invalid image URL>" alt="Image with
special characters">< within the
src attribute as the start of a new XML element.
<img src="<invalid image
URL>" alt="Image with special characters">< symbol is displayed literally as
"<" because it's escaped using a character reference.2. Greater Than (>)
<button onclick="alert('This message has > in
it')">Click Me</button>> within the onclick attribute might be
interpreted as the end of the opening <button> tag.<button onclick="alert('This message has
> in it')">Click Me</button>> symbol is displayed literally as
">" using the character reference.3. Ampersand (&)
<a
href="http://www.example.com¶m1=value1">Link Text</a>& as the start of a character reference, leading to
errors.<a
href="http://www.example.com?param1=value1">Link Text</a>& is used for its intended
purpose within a URL query string (separating parameters).4. Apostrophe (')
<input type="text" value="He said, 'Isn't this
cool?'"><input type="text"
value="He said, "Isn't this cool?""><input type='text' value='He said, "Isn\'t this cool?"'> (Escape the
double quote within the value)
5. Double Quote (")
<p title="This title has a "double quote"
inside."><p title='This title
has a "double quote" inside.'> (Escape the double quote within the value)
<p
title="This title has a "double quote" inside."> (Escape
the double quote using a character reference)Remember: The specific characters that need escaping can vary depending on the context and the XML parser being used. It's always a good practice to escape these characters when in doubt to ensure proper parsing and avoid potential errors.
Markdown uses backslashes (\) to escape a small set of characters that would
otherwise have special formatting meanings within the language. Here's a breakdown of some
common escape characters in Markdown:
1. Asterisk (\*)
This sentence includes an asterisk \* for
emphasis. (Output: This sentence includes an asterisk * for emphasis.)2. Underscore (\_)
We have a_special_case here that shouldn't be
italicized. (Output: We have a_special_case here that shouldn't be
italicized.)3. Backtick (\)
The command is written as \ls`.(Output: The
command is written asls`.)4. Hash (\#)
Use \# marks sparingly for better readability.
(Output: Use # marks sparingly for better readability.)5. Other Characters
\(
and \)), square brackets (\[ and \]), curly
braces (\{ and \}), plus sign (\+), minus sign
(\-), and pipe (\|) to display them literally.Important Notes:
By understanding these escape characters, you can gain more control over how your text appears in Markdown documents.
Escape characters are a fundamental concept in many programming languages beyond JSON and JavaScript. They serve the same core purpose: to allow you to represent special characters literally within strings or code. Here are some examples of languages that use escape characters and how they might be applied:
C/C++/Java:
\) for escaping
characters like:
\n for newline\t for tab\" for double quote within a string\' for single quote within a string (using double quotes as string
delimiters)\ followed by three octal digits) and
hexadecimal (\x followed by two hexadecimal digits) escapes for a wider
range of characters.Python:
r or R) to
include backslashes literally.
r"\n" represents a backslash followed by an n.\' for single quote within a string (using double quotes as
delimiters)\" for double quote within a string (using single quotes as
delimiters)PHP:
\) for escaping:
\n for newline\t for tab\" for double quote within a string\' for single quote within a stringRegular Expressions:
\d might match any digit, \w any word
character, and \. might match a literal period (.).
Remember: