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Introduction to Programming With Java
Lecture - 11 UMESH PATIL (umesh_at_cse.iitb.ac.in)
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Contents for Todays Lecture

• Programming practice Program for morphological
  analysis of English nouns.

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Problem
Write a Java program that finds out the root
suffix of the given noun plural in English. Also
print the morphology rule applied for forming the
plural. Sample input output Input boys
Output root boy suffix s Morphology
rule W ? Ws Input indices
Output root index suffix ices
Morphology rule Wex ? Wices
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Plurals in English

• Example
• boy ? boys
• bus ? buses
• lady ? ladies
• leaf ? leaves
• datum ? data
• formula ? formulae
• index ? indices
• matrix ? matrices
• radius ? radii
• cherub ? cherubim

• Morphology Rule
• W ? Ws
• W ? Wes
• Wy ? Wies
• Wf ? Wves
• Wum ? Wa
• W ? We
• Wex ? Wices
• Wx ? Wces
• Wus ? Wi
• W ? Wim

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Algorithm

1. Read the input word
2. Find the suffix
3. Remove suffix get the root
4. If needed, prepare the correct rooteg. indices ?
   ind ? ind ex index
5. Print the output

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Required Methods of String class

• boolean endsWith(String suffix)Returns true if
  the string ends with the specified suffix false
  otherwise. Parameters the String suffix.
• eg. If s indices thens.endsWith(ices) will
  return trues.endsWith(s) will return
  trues.endsWith() will return
  trues.endsWith(indices) will return
  trueButs.endsWith(ice) will return false

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Required Methods of String class continued

• String substring(int beginIndex, int
  endIndex)Returns a new string that is a
  substring of the current string. The substring
  begins at the specified beginIndex and extends to
  the character at index endIndex - 1. It will give
  error (throw exception) if the beginIndex is
  negative, or endIndex is larger than the length
  the string, or beginIndex is larger than
  endIndex.ParametersbeginIndex - the beginning
  index, inclusive.endIndex - the ending index,
  exclusive.
• eg. If s mississippi thens.substring(0,4)
  will return misss.substring(6,9) will return
  sips.substring(0,11) will return
  mississippis.substring(0,0) will return

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Required Methods of String class continued

• int lastIndexOf(String str)Returns the index
  within the current string of the rightmost
  occurrence of the specified substring. If str
  does not occur as a substring, -1 is
  returned.Parameters str - the substring to
  search for.
• eg. If s mississippi thens.lastIndexOf(is)
  will return 4s.lastIndexOf(i) will return
  10s.lastIndexOf() will return
  11s.lastIndexOf(mississippi) will return
  0Ands.lastIndexOf(abc) will return -1

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Required Methods of String class continued

• String concat(String str)Returns a string after
  concatenating the specified string, ie. str, to
  the end of the current string.Parametersstr -
  the string that is concatenated to the end of the
  current string.
• eg. if s man thens.concat(go) will return
  mangos.concat() will return man
• Detailed explanation of the String class.

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Core Part of the Program
Suppose input word indices if
(word.endsWith("ices")) // word indices
suffix "ices" i word.lastIndexOf("ices") /
/ i 3 root word.substring(0,i) // root
ind root root.concat("ex") // root
index morphRule "Wex ?
Wices"
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Some Testing

• matrix ? matrices
• life ? lives
• analysis ? analyses
• criterion ? criteria
• Does the program work for these examples?
• If yes, how?
• If no, why?

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Assignment

• Do the morphological analysis of the following
  inflected verbs in English and write a Java
  program that finds out the root suffix of the
  given inflected verb. Also print the morphology
  rule that is applied.
• fetch ? fetches, fetching, fetched
• carry ? carries, carrying, carried
• enjoy ? enjoys, enjoying, enjoyed
• burn ? burns, burning, burnt
• beat ? beats, beating, beaten
• forbid ? forbids, forbidding, forbided, forbidden
• blow ? blows, blowing, blowed, blown
• save ? saves, saving, saved

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Assignment continued
say ? says, saying, said drop ? drops, dropping,
dropped admit ? admits, admitting, admitted repel
? repels, repelling, repelled dog ? dogs,
dogging, dogged can ? cans, canning, canned spur
? spurs, spurring, spurred stem ? stems,
stemming, stemmed stab ? stabs, stabbing,
stabbed kid ? kids, kidding, kidded mimic ?
mimics, mimicking, mimicked
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To Remind
The best way to learn programming is writing a
lot of programs on your own.
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End
Thank you ?
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