Difference between revisions of "Cookbook/Interactivity"

From HaskellWiki
Jump to: navigation, search
(smaller headlines)
(Reading a string)
Line 1: Line 1:
== Reading a string ==
 
  +
{| class="wikitable"
Strings can be read as input using [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AgetLine getLine].
 
  +
|-
<haskell>
 
  +
! Problem
  +
! Solution
  +
! Examples
  +
|-
 
| reading a string
 
| [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AgetLine getLine]
 
|<haskell>
 
Prelude> getLine
 
Prelude> getLine
Foo bar baz
+
Foo bar baz --> "Foo bar baz"
"Foo bar baz"
 
 
</haskell>
 
</haskell>
  +
|}
   
 
== Printing a string ==
 
== Printing a string ==

Revision as of 09:00, 2 August 2009

Problem Solution Examples
reading a string getLine
Prelude> getLine
Foo bar baz          --> "Foo bar baz"

Printing a string

Strings can be output in a number of different ways.

Prelude> putStr "Foo"
FooPrelude>

As you can see, putStr does not include the newline character `\n'. We can either use putStr like this:

Prelude> putStr "Foo\n"
Foo

Or use putStrLn, which is already in the Standard Prelude

Prelude> putStrLn "Foo"
Foo

We can also use print to print a string, including the quotation marks.

Prelude> print "Foo"
"Foo"

Parsing command line arguments

TODO