Hell, I am new to play framework and Scala. I don't know how to display special characters like #, -, "" as text.
Help!
If I got your question right, you are asking how to escape special characters in scala. It's pretty much same as other languages. using escape character \
val str = " \\\" " //output str: \"
or follow the below special syntax to store in string value with exactly what is inside the triple quotes.
val str = """ \" """ //output str: \"
Related
I have a string like this in below and I want replace space with backslash and space.
let test: String = "Hello world".replacingOccurrences(of: " ", with: "\ ")
print(test)
But Xcode make error of :
Invalid escape sequence in literal
The code in up is working for any other character or words, but does not for backslash. Why?
Backslash is used to escape characters. So to print a backslash itself, you need to escape it. Use \\.
For Swift 5 or later you can avoid needing to escape backslashes using the enhanced string delimiters:
let backSlashSpace = #"\ "#
If you need String interpolation as well:
let value = 5
let backSlashSpaceWithValue = #"\\#(value) "#
print(backSlashSpaceWithValue) // \5
You can use as many pound signs as you wish. Just make sure to mach the same amount in you string interpolation:
let value = 5
let backSlashSpaceWithValue = ###"\\###(value) "###
print(backSlashSpaceWithValue) // \5
Note: If you would like more info about this already implemented Swift evolution proposal SE-0200 Enhancing String Literals Delimiters to Support Raw Text
How to replace the double quote by \":
val s = """I am "groot"."""
so the output will be """I am \"groot\"."""
I tried with but no luck
s.replaceAll('"', '\"')
So #Tanjin provides the correct solution. However, the reason your solution does not work is this.
s.replaceAll('"', '\"')
Backslashes have special meaning in string and character literals, so '\"' compiles down to just the quote character. Running in the REPL will show you this
scala> '\"'
res2: Char = "
Meanwhile, using triple-quote strings disables this behavior.
scala> """\""""
res3: String = \"
Try this way:
s.replaceAll("\"", "\\\\\"")
How does this work:
s.replace(""""""", """\"""")
I am working on the exercises from https://www.scala-exercises.org/std_lib/formatting
For the following question, m answer seems incorrect but I do not know why.
val c = 'a' //unicode for a
val d = '\141' //octal for a
val e = '\"'
val f = '\\'
"%c".format(c) should be("a") //my answers
"%c".format(d) should be("a")
"%c".format(e) should be(")
"%c".format(f) should be(\)
your answer should be enclosed in quotes
"%c".format(e) should be("\"")
"%c".format(f) should be("\\")
because it wouldn't recognize string unless it's enclosed in quotes
Your last two lines are invalid Scala code and cannot be compiled:
// These are wrong
"%c".format(e) should be(")
"%c".format(f) should be(\)
The be() function needs to be passed a String, and neither of those calls are being passed a String. A String needs to start and end with a double-quote (there are some exceptions).
// In this case you started a String with a double-quote, but you are never
// closing the string with a second double-quote
"%c".format(e) should be(")
// In this case you are missing both double-quotes
"%c".format(f) should be(\)
In this case the code should be:
"%c".format(e) should be("\"")
"%c".format(f) should be("\\")
If you want a character to be treated literally in a String, you need to "escape" it with a backslash. So if you want to literally show a double-quote, you need to prefix it with a backslash:
\"
And as a String:
"\""
Similarily for a backslash:
\\
As a String:
"\\"
Using an IDE makes this easier to see. Using IntelliJ the String is green but the special non-literal characters are highlighted in orange.
Check quote signs.
https://www.tutorialspoint.com/scala/scala_strings.htm
https://docs.scala-lang.org/overviews/core/string-interpolation.html
https://learnxinyminutes.com/docs/scala/
You can run Scala code online and check yourself here:
https://scastie.scala-lang.org
https://ideone.com/
I need to make some Windows file paths that contain spaces into string literals in Scala. I have tried wrapping the entire path in double quotes AND wrapping the entire path in double quotes with each directory name that has a space with single quotes. Now it is wanting an escape character for "\Jun" in both places and I don't know why.
Here are the strings:
val input = "R:\'Unclaimed Property'\'CT State'\2015\Jun\ct_finderlist_2015.pdf"
val output = "R:\'Unclaimed Property'\'CT State'\2015\Jun"
Here is the latest error:
The problem is with the \ character, that has to be escaped.
This should work:
val input = "R:\\Unclaimed Property\\CT State\\2015\\Jun.ct_finderlist_2015.pdf"
val output = "R:\\Unclaimed Property\\CT State\\2015\\Jun"
A cleaner way to create string literals is to use triple quotes.
You can wrap your string directly in triple quotes without escaping special characters. And you can put multiple lines string in it.
It's much easier to code and read.
For example
val input =
"""
|R:\Unclaimed Property\CT State\2015\Jun.ct_finderlist_2015.pdf
"""
To add a variable to the string, do it like the following by adding "$variableName".
val input =
s"""
|R:\Unclaimed Property\$variablePath\CT State\2015\Jun.ct_finderlist_2015.pdf
"""
I am fairly new to scala and I have the need to convert a string that is pipe delimited to one that is comma delimited, with the values wrapped in quotes and any quotes escaped by "\"
in c# i would probably do this like this
string st = "\"" + oldStr.Replace("\"", "\\\\\"").Replace("|", "\",\"") + "\""
I haven't validated that actually works but that is the basic idea behind what I am trying to do. Is there a way to do this easily in scala?
Similarly:
val st = "\"" + oldStr.replaceAll("\"", "\\\\\"").replaceAll("\\|", "\",\"") + "\""
Could also be:
val st = oldStr.replaceAll("\"","\\\\\"").split("\\|").mkString("\"","\",\"","\"")