Haskell Strings
A string is a value that holds text. Haskell writes text inside double quotes.
++ joins two strings
The ++ operator joins the second string to the end of the first one.
main :: IO ()
main = putStrLn ("Hello, " ++ "Ana")length counts the characters
length counts every character in the string. The word Haskell has seven letters.
main :: IO ()
main = print (length "Haskell")print keeps the double quotes
print writes a string in its shown form. The shown form keeps the double quotes.
main :: IO ()
main = print "Hello"Example
main :: IO ()
main = print (length ("Ana" ++ " Verma"))Key points
- String: a String value holds text.
- Quotes: text is written between double quotes to make a string.
- Joining: the ++ operator joins two strings into one longer string.
- length: length counts the characters in a string.
- Empty string: the value "" is a string with no characters.
In this example, ++ joins "Ana" and " Verma" into one string, length counts its nine characters, and print writes 9.
Note
print shows a string with double quotes around it.
Try it Yourself
Edit the code, then press Run.
Running is simulated · Haskell Playground
Exercise
What does print (length "code") print?