Personal tools

Cookbook/Interactivity

From HaskellWiki

< Cookbook(Difference between revisions)
Jump to: navigation, search
(3 intermediate revisions by one user not shown)
Line 1: Line 1:
  +
== Input and output ==
  +
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
Line 12: Line 14:
 
</haskell>
 
</haskell>
 
|-
 
|-
| printing a string in a new line
+
| printing a string with a newline character
 
| [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AputStrLn putStrLn]
 
| [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AputStrLn putStrLn]
 
|<haskell>
 
|<haskell>
 
Prelude> putStrLn "Foo"
 
Prelude> putStrLn "Foo"
 
Foo
 
Foo
  +
Prelude>
 
</haskell>
 
</haskell>
 
|-
 
|-
Line 27: Line 30:
 
|}
 
|}
   
== Printing a string ==
+
Strings can be output in a number of different ways.
 
<haskell>
 
Prelude> putStr "Foo"
 
FooPrelude>
 
</haskell>
 
As you can see, [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AputStr putStr] does not include the newline character `\n'. We can either use putStr like this:
 
<haskell>
 
Prelude> putStr "Foo\n"
 
Foo
 
</haskell>
 
Or use [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AputStrLn putStrLn], which is already in the Standard Prelude
 
<haskell>
 
Prelude> putStrLn "Foo"
 
Foo
 
</haskell>
 
We can also use [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3Aprint print] to print a string, '''including the quotation marks.'''
 
<haskell>
 
Prelude> print "Foo"
 
"Foo"
 
</haskell>
 
   
 
== Parsing command line arguments ==
 
== Parsing command line arguments ==

Revision as of 09:08, 2 August 2009

1 Input and output

Problem Solution Examples
printing a string putStr
Prelude> putStr "Foo"
FooPrelude>
printing a string with a newline character putStrLn
Prelude> putStrLn "Foo"
Foo
Prelude>
reading a string getLine
Prelude> getLine
Foo bar baz          --> "Foo bar baz"


2 Parsing command line arguments

TODO