Chapter 13, Problem 14PE

Program Plan Intro

Creating Substrings

Program plan:

Filename: “SubstringGenerator.java”

This program file is used to define a class “SubstringGenerator”. In the code,

• Import the required packages.
• Define a class “SubstringGenerator”.
  • Declare a string class member “word”.
  • Define a constructor “SubstringGenerator ()”.
    • Initialize the “word”.
  • Define a method “getSubstring()”.
    • Create an array list “result”.
    • If the length of the “word” is “0”.
      • Call the method “add()” to add the “word” to array list.
        • Create a string “shorterWord” to hold a substring.
        • Create an object “shorterSubstringGenerator” of class “SubstringGenerator”.
        • Create an array list “shorterWordSubstrings” to hold the substrings.
        • Iterate a “for” loop
        • • Fill the array list “result”.
        • Iterate a “for” loop.
        • • Create the substrings of the string “word” and add it to “result”.

Filename: “SubstringGeneratorDemo.java”

This program file is used to define a class “SubstringGeneratorDemo” to test the class “SubstringGenerator”. In the code,

• Import the required packages.
• Define a class “SubstringGeneratorDemo”.
  • Define a method “main()”.
    • Create the object “generator” of class “SubstringGenerator” to initialize “word” with value “rum”.
    • Create an array list “substrings” and fill it by calling the method “getSubstrings()”.
    • Call the method “sort()” of “Collections”to sort the substrings.
    • Print the “substrings”.
    • Print the expected substrings.
    • Create the object “generator” of class “SubstringGenerator” to initialize “word” with value “paper”.
    • Fill the array list by calling the method “getSubstrings()”.
    • Call the method “sort()” of “Collections”to sort the substrings.
    • Print the “substrings”.
    • Print the expected substrings.
    • Create the object “generator” of class “SubstringGenerator” to initialize “word” with value “coffee”.
    • Fill the array list by calling the method “getSubstrings()”.
    • Call the method “sort()” of “Collections”to sort the substrings.
    • Print the “substrings”.
    • Print the expected substrings.