Strings

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• Misc
  • Final
    • Tuesday, May 12, 8:00 AM
    • Comprehensive, but emphasizing material since 2nd hour exam (e.g., cell arrays, strings, files, etc.)
    • Designed for 2 hours, you’ll have 3
    • Otherwise similar rules and format to hour exams
    • Donuts and cider
  • SOFIs
    • Fill them out via http://go.geneseo.edu/sofi_survey
    • Useful to me in improving courses
• Questions?
  • Make random strings via randi and char functions
    

    >> char(65)
    ans =
    A
    >> nums = randi( 255, [1 10] )
    nums =
       208   231    33   233   162    25    72   140   245   247
    >> char( nums )
    ans =
    -Á!È¢ Hå1~

• Strings
  • Sections 7.1 and 7.2
    • Basics:
      • Substring = part of string, e.g., 'cat' in 'I have a cat'
      • Whitespace = space, tab, etc.
      • Control characters can’t be printed
      • May have leading and trailing blanks at start and end of string; can be removed
      • input function
      • * Strings are vectors, vector functions work on them
        • e.g., length, indexing, size
      • Can have matrices of strings
    • * String operations
      • * Concatenation = join strings together
        • As vectors
        • Or via strcat
        • char function
      • Blanks ?
      • sprintf creates string instead of printing ?
      • deblank removes blanks from end
      • strtrim removes leading and trailing blanks
      • upper and lower change case
      • * comparisons via strcmp, returns 1 if equal, 0 if not
      • * replacing parts of strings via strrep
  • Examples
    

    >> blanks( 3 )
    ans =
       
    >> length(ans)
    ans =
         3
    >> s = 'hello world'
    s =
    hello world
    >> fprintf( 'My string is "%s" of length %f\n', s, length(s) );
    My string is "hello world" of length 11.000000
    >> formatted = sprintf('My string is "%s" of length %f', s, length(s) );
    >> formatted
    formatted =
    My string is "hello world" of length 11.000000
    >> length(formatted)
    ans =
        46
    >> formatted( 10:20 )
    ans =
     is "hello 
    >> x = pi/2
    >> x =
        1.5708
    >> stringx = sprintf('%s',x) 
    stringx =
    1.570796e+00
    >> stringx2 = sprintf( '%f', x )
    stringx2 =
    1.570796
    >> stringx2 + 17
    ans =
        66    63    70    72    65    72    74    71
    >> stringx2 + 0
    ans =
        49    46    53    55    48    55    57    54

• Mad Libs Project
  • Handout
  • Examples of how your solution should behave. Note that there is a single function that plays different Mad Libs depending on its argument
    

    >> load fairytale
    >> load courseDescription
    >> play(fairyTale)
    Give me a...
    Adjective favorite
    Verb Ending in "ing" spelunking
    Adjective purple
    Noun flower
    Past-Tense Verb grew
    Adjective short
    Noun door
    Adjective shiny
    Verb smile
    Noun puppy
    Adverb quickly
    Beverage coolaid
    
    Once upon a time there was a favorite prince. One day, while the prince was spelunking
    he met a purple wizard disguised as a flower. Not realizing what he was doing, the
    prince grew the wizard. This made the wizard very short. In a twinkling of an eye,
    he turned the prince into a door. "Never mind," thought the prince, "surely a shiny
    princess will come along and smile me so I turn back into a puppy. Alas! Little did
    the prince know that all the princesses were busy getting college degrees, while the
    princes quickly sat around drinking coolaid. The end.
    >> play( courseDescription )
    Give me a...
    Subject of Study ... etc ...

• Next
  • Lab (and/or project) time

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