I have following string saved in database:
<p>ampersand (&), bracket(<>), quotation marks (""'')</p>\r\n
I need to encode the special symbols and get a string
<p>ampersand (&), bracket(<>), quotation marks (""'')</p>
I used CGI library to encoding:
CGI::unescapeHTML("<p>ampersand (&), bracket(<>), quotation marks (""'')</p>\r\n")
the method returns "<p>ampersand (&), bracket(<>), quotation marks (\"\"'')</p>\r\n"
but should be
<p>ampersand (&), bracket(<>), quotation marks (""'')</p>
It's actually correct (the method). It's returning what you want.
The \ you are seeing before the double quotes are just artifacts of rendering a string with embedded double quotes, so that they're not interpreted as the end of the string.
Related
I tried to split by "\", but this character is so special in Lua, even if I use escape character "%", the IDE shows an error Unterminated String constant
local index = string.find("lua. is \wonderful", "%\", 1)
To insert backslash \ into a quoted string, escape it with itself: "\\". \ is the escape character in regular quoted strings, so it is escaped with \. Or you can use the long string syntax, which doesn't allow escape sequences, as already pointed out: [[\]].
Percent is only an escape character in a string that is being used as a pattern, so it is used before the magical characters ^$()%.[]*+-? in the second argument to string.find, string.match, string.gmatch, and string.gsub, and %% represents % in the third argument to string.gsub.
The percent is still there in the string that is stored in memory, but backslash escape sequences are replaced with the corresponding character. \\ becomes \ when the string is stored in memory, and if you count the number of backslashes in a string "\\" using string.gsub, it will only find one: select(2, string.gsub("\\", "\\", "")) returns 1.
Apple's documentation states the followings about the value of a key.
Default value strings may contain extended ASCII characters.
...
Just as in C, some characters must be prefixed with a backslash before you can include them in the string. These characters include double quotation marks, the backslash character itself, and special control characters such as linefeed (\n) and carriage returns (\r).
In my experience it did't matter if I used ' or \', after calling the localizedStringForKey:value:table: method the result was the same.
question: why?
question: is there an explicit list somewhere which lists all the characters which must be escaped and which can be (meaning that the result will be the same)?
Can someone please tell me how can I print something in following way "with" double quotes.
"Double Quotes"
With a backslash before the double quote you want to insert in the String:
let sentence = "They said \"It's okay\", didn't they?"
Now sentence is:
They said "It's okay", didn't they?
It's called "escaping" a character: you're using its literal value, it will not be interpreted.
With Swift 4 you can alternatively choose to use the """ delimiter for literal text where there's no need to escape:
let sentence = """
They said "It's okay", didn't they?
Yes, "okay" is what they said.
"""
This gives:
They said "It's okay", didn't they?
Yes, "okay" is what they said.
With Swift 5 you can use enhanced delimiters:
String literals can now be expressed using enhanced delimiters. A string literal with one or more number signs (#) before the opening quote treats backslashes and double-quote characters as literal unless they’re followed by the same number of number signs. Use enhanced delimiters to avoid cluttering string literals that contain many double-quote or backslash characters with extra escapes.
Your string now can be represented as:
let sentence = #"They said "It's okay", didn't they?"#
And if you want add variable to your string you should also add # after backslash:
let sentence = #"My "homepage" is \#(url)"#
For completeness, from Apple docs:
String literals can include the following special characters:
The escaped special characters \0 (null character), \ (backslash), \t
(horizontal tab), \n (line feed), \r (carriage return), \" (double
quote) and \' (single quote)
An arbitrary Unicode scalar, written as
\u{n}, where n is a 1–8 digit hexadecimal number with a value equal to
a valid Unicode code point
which means that apart from being able to escape the character with backslash, you can use the unicode value. Following two statements are equivalent:
let myString = "I love \"unnecessary\" quotation marks"
let myString = "I love \u{22}unnecessary\u{22} quotation marks"
myString would now contain:
I love "unnecessary" quotation marks
According to your needs, you may use one of the 4 following patterns in order to print a Swift String that contains double quotes in it.
1. Using escaped double quotation marks
String literals can include special characters such as \":
let string = "A string with \"double quotes\" in it."
print(string) //prints: A string with "double quotes" in it.
2. Using Unicode scalars
String literals can include Unicode scalar value written as \u{n}:
let string = "A string with \u{22}double quotes\u{22} in it."
print(string) //prints: A string with "double quotes" in it.
3. Using multiline string literals (requires Swift 4)
The The Swift Programming Language / Strings and Characters states:
Because multiline string literals use three double quotation marks instead of just one, you can include a double quotation mark (") inside of a multiline string literal without escaping it.
let string = """
A string with "double quotes" in it.
"""
print(string) //prints: A string with "double quotes" in it.
4. Using raw string literals (requires Swift 5)
The The Swift Programming Language / Strings and Characters states:
You can place a string literal within extended delimiters to include special characters in a string without invoking their effect. You place your string within quotation marks (") and surround that with number signs (#). For example, printing the string literal #"Line 1\nLine 2"# prints the line feed escape sequence (\n) rather than printing the string across two lines.
let string = #"A string with "double quotes" in it."#
print(string) //prints: A string with "double quotes" in it.
I need to add some french translation into iOS Application. But I don know how to use single qute char in the Localizable.strings file.
For example text :
"Invalid username or password."="Nom d'utilisateur ou mot de passe incorrect.";
Causes an error. I've tried adding backslashes, but it havn't worked as well.
Using Special Characters in String Resources Just as in C, some
characters must be prefixed with a backslash before you can include
them in the string. These characters include double quotation marks,
the backslash character itself, and special control characters such as
linefeed (\n) and carriage returns (\r).
From:
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/LoadingResources/Strings/Strings.html
Did you try escaping it with a backslash?
"\'"
As a last resort you could use direct U codes:
You can include arbitrary Unicode characters in a value string by
specifying \U followed immediately by up to four hexadecimal digits.
The four digits denote the entry for the desired Unicode character;
for example, the space character is represented by hexadecimal 20 and
thus would be \U0020 when specified as a Unicode character. This
option is useful if a string must include Unicode characters that for
some reason cannot be typed. If you use this option, you must also
pass the -u option to genstrings in order for the hexadecimal digits
to be interpreted correctly in the resulting strings file. The
genstrings tool assumes your strings are low-ASCII by default and only
interprets backslash sequences if the -u option is specified.
The apostrophe should be \U0027
Trying to enter the following text fails:
MERGE (people:People {Person:'Abe N. O'Sullivan'})
Replacing the apostrophe with a ’ works, but I wonder if there is a more ellegant solution.
Use double quotes, and it will work fine:
MERGE (people:People {Person:"Abe N. O'Sullivan"})
Note if this were the name of a property, you can use backticks to escape the name of a property that has spaces or special characters in it. For text literals, you can surround them with either single or double quotes. If you want to put a quote inside of a text literal quote, you either need to use the other kind of quote to surround the string, or you need to escape it with backslash, I believe.