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== Reading a string ==
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== Input and output ==
Strings can be read as input using [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AgetLine getLine].
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<haskell>
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Prelude> getLine
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Foo bar baz
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"Foo bar baz"
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</haskell>
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== Printing a string ==
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{| class="wikitable"
Strings can be output in a number of different ways.
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|-
<haskell>
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!  Problem
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!  Solution
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!  Examples
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|-
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|  printing a string
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|  [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AputStr putStr]
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|<haskell>
 
Prelude> putStr "Foo"
 
Prelude> putStr "Foo"
 
FooPrelude>
 
FooPrelude>
 
</haskell>
 
</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:
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|-
<haskell>
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|  printing a string with a newline character
Prelude> putStr "Foo\n"
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| [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AputStrLn putStrLn]
Foo
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|<haskell>
</haskell>
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Or use [http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AputStrLn putStrLn], which is already in the Standard Prelude
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<haskell>
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Prelude> putStrLn "Foo"
 
Prelude> putStrLn "Foo"
 
Foo
 
Foo
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Prelude>
 
</haskell>
 
</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.'''
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|-
<haskell>
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|  reading a string
Prelude> print "Foo"
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[http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#v%3AgetLine getLine]
"Foo"
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|<haskell>
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Prelude> getLine
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Foo bar baz          --> "Foo bar baz"
 
</haskell>
 
</haskell>
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|}
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 +
  
 
== Parsing command line arguments ==
 
== Parsing command line arguments ==
  
 
TODO
 
TODO

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