Building Utility Class for String Array Objects

• Objective

  • Ensure StringArrayUtilsTest passes each test by completing the methods stubbed out in the class StringArrayUtils
    • String getFirstElement(String[] array)
    • String getSecondElement(String[] array)
    • String getLastElement(String[] array)
    • String getSecondToLastElement(String[] array)
    • boolean contains(String[] array, String value)
    • String[] reverse(String[] array)
    • boolean isPalindromic(String[] array)
    • boolean isPangramic(String[] array)
    • int getNumberOfOccurrences(String[] array, String value)
    • String[] removeValue(String[] array, String value)
    • String[] removeConsecutiveDuplicates(String[] array)
    • String[] packConsecutiveDuplicates(String[] array)

• Purpose

  • To establish greater familiarity with loops and arrays.
  • To demonstrate the implementation of a Utility class

String getFirstElement(String[] array)

• Description
  • Given an array of String objects, return the first element of the array.

Example 1

• Sample Script

// : Given
String[] array = {"quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
String outcome = StringArrayUtils.getFirstElement(array);

// : Then
System.out.println(outcome);

• Sample Output

quick

Example 2

• Sample Script

// : Given
String[] array = {"brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
String outcome = StringArrayUtils.getFirstElement(array);

// : Then
System.out.println(outcome);

• Sample Output

brown

Example 3

• Sample Script

// : Given
String[] array = {"fox", "jumps", "over", "the", "lazy", "dog"};

// : When
String outcome = StringArrayUtils.getFirstElement(array);

// : Then
System.out.println(outcome);

• Sample Output

fox

String getSecondElement(String[] array)

• Description
  • Given an array of String objects, return the first element of the array.

Example 1

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
String outcome = StringArrayUtils.getSecondElement(array);

// : Then
System.out.println(outcome);

• Sample Output

quick

Example 2

• Sample Script

// : Given
String[] array = {"quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};    
// : When
String outcome = StringArrayUtils.getFirstElement(array);

// : Then
System.out.println(outcome);

• Sample Output

brown

Example 3

• Sample Script

// : Given
String[] array = {"brown", "fox", "jumps", "over", "the", "lazy", "dog"};    
// : When
String outcome = StringArrayUtils.getFirstElement(array);

// : Then
System.out.println(outcome);

• Sample Output

fox

String getLastElement(String[] array)

• Description
  • Given an array of String objects, return the last element of the array.

Example 1

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
String outcome = StringArrayUtils.getLastElement(array);

// : Then
System.out.println(outcome);

• Sample Output

dog

Example 2

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy"};

// : When
String outcome = StringArrayUtils.getLastElement(array);

// : Then
System.out.println(outcome);

• Sample Output

lazy

Example 3

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over"};

// : When
String outcome = StringArrayUtils.getLastElement(array);

// : Then
System.out.println(outcome);

• Sample Output

the

String getSecondToLastElement(String[] array)

• Description
  • Given an array of String objects, return the next-to-last element of the array.

Example 1

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
String outcome = StringArrayUtils.getSecondToLastElement(array);

// : Then
System.out.println(outcome);

• Sample Output

lazy

Example 2

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "lazy"};

// : When
boolean outcome = StringArrayUtils.getNextToLastElement(array);

// : Then
System.out.println(outcome);

• Sample Output

over

Example 3

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over"};

// : When
boolean outcome = StringArrayUtils.getNextToLastElement(array);

// : Then
System.out.println(outcome);

• Sample Output

jumps

boolean contains(String[] array, String value)

• Description
  • Given an array of String objects named array and a String object named value
    return true if value appears in arrays.

Example 1

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
boolean outcome = StringArrayUtils.contains(array, "the");

// : Then
System.out.println(outcome);

• Sample Output

true

Example 2

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
boolean outcome = StringArrayUtils.contains(array, "potatoes");

// : Then
System.out.println(outcome);

• Sample Output

false

String[] reverse(String[] array)

• Description
  • Given an array of String objects, return an array with identical contents in reverse order.

Example 1

• Sample Script

// : Given
String[] array = {"the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"};

// : When
boolean outcome = StringArrayUtils.contains(array, "the");

// : Then
System.out.println(outcome);

• Sample Output

[dog, lazy, the, over, jumps, fox, brown, quick, the]

Example 2

• Sample Script

// : Given
String[] array = {"Pack", "my", "box", "with", "five", "dozen", "liquor", "jugs"};

// : When
boolean outcome = StringArrayUtils.contains(array, "potatoes");

// : Then
System.out.println(outcome);

• Sample Output

[jugs, liquor, dozen, five, with, box, my, Pack]

Example 3

• Sample Script

// : Given
String[] array = {"The", "quick", "onyx", "goblin", "jumps", "over", "the", "lazy", "dwarf"};

// : When
boolean outcome = StringArrayUtils.contains(array, "potatoes");

// : Then
System.out.println(outcome);

• Sample Output

[dwarf, lazy, the, over, jumps, goblin, onyx, quick, The]

boolean isPalindromic(String[] array)

• Description
  • A palindrome is a sequence that is the same backwards and forwards.
  • Given an array of String objects, return true if the array is palindromic.

Example 1

• Sample Script

// : Given
String[] array = {"a", "b", "c", "b", "a"}

// : When
boolean outcome = StringArrayUtils.isPalindrome(array);

// : Then
System.out.println(outcome);

• Sample Output

true

Example 2

• Sample Script

// : Given
String[] array = {"Is this a plaindrome?", "This is a plaindrome", "Is this a palindrome?"}

// : When
boolean outcome = StringArrayUtils.isPalindrome(array);

// : Then
System.out.println(outcome);

• Sample Output

true

Example 3

• Sample Script

// : Given
String[] array = {"Is this a plaindrome?", "This is not a plaindrome", "Is this a palindrome?", "This is not a palindrome"}

// : When
boolean outcome = StringArrayUtils.isPalindrome(array);

// : Then
System.out.println(outcome);

• Sample Output

false

boolean isPangramic(String[] array)

• Description
  • A pangram is a sequence that contains all letters of the alphabet.
  • Given an array of String objects, return true if the array is palindromic.

Example 1

• Sample Script

// : Given
String[] array = {"The quick brown", "Fox jumps over", "The lazy dog"}

// : When
boolean outcome = StringArrayUtils.isPangramic(array);

// : Then
System.out.println(outcome);

• Sample Output

true

Example 2

• Sample Script

// : Given
String[] array = {"The", "quick", "onyx", "goblin", "jumps", "over", "the", "lazy", "dwarf"};

// : When
boolean outcome = StringArrayUtils.isPangramic(array);

// : Then
System.out.println(outcome);

• Sample Output

true

int getNumberOfOccurrences(String[] array, String value)

• Description
  • Given an array of String objects named array and a String object named value
    return the number of times value appears in arrays

Example 1

• Sample Script

// : Given
String[] array = {"aba", "aba", "baa", "bab", "bba", "bba", "bba", "bba", "bbb", "bbb"};

// : When
int numberOfOccurrences = StringArrayUtils.getNumberOfOccurrences(array, "bba");

// : Then
System.out.println(numberOfOccurrences);

• Sample Output

4

Example 2

• Sample Script

// : Given
String[] array = {"aba", "aba", "baa", "bab", "bba", "bba", "bba", "bba", "bbb", "bbb"};

// : When
int numberOfOccurrences = StringArrayUtils.getNumberOfOccurrences(array, "bbb");

// : Then
System.out.println(numberOfOccurrences);

• Sample Output

2

Example 3

• Sample Script

// : Given
String[] array = {"aba", "aba", "baa", "bab", "bba", "bba", "bba", "bba", "bbb", "bbb"};

// : When
int numberOfOccurrences = StringArrayUtils.getNumberOfOccurrences(array, "baa");

// : Then
System.out.println(numberOfOccurrences);

• Sample Output

1

String[] removeConsecutiveDuplicates(String[] array)

• Description
  • Given an array of String objects, return an array of Strings with conseuctive duplicates removed.

Example 1

• Sample Script

// : Given
String[] array = {"aba", "aba", "baa", "bab", "bba", "bba", "bba", "bba", "bbb", "bbb"};

// : When
String[] actual = StringArrayUtils.removeConsecutiveDuplicates(array);

// : Then
System.out.println(Arrays.toString(actual));

• Sample Output

[aba, baa, bab, bba, bbb];

Example 2

• Sample Script

// : Given
String[] array = {"aba", "aba", "baa", "bab", "bba", "zzz", "bba", "bba", "bba", "bbb", "bbb"};

// : When
String[] actual = StringArrayUtils.removeConsecutiveDuplicates(array);

// : Then
System.out.println(Arrays.toString(actual));

• Sample Output

[aba, baa, bab, bba, zzz, bba, bbb];

Example 3

• Sample Script

// : Given
String[] array = {"aba", "aba", "baa", "bab", "bba", "zzz", "bba", "bba", "bba", "bbb", "bbb", "aba", "bbb"};

// : When
String[] actual = StringArrayUtils.removeConsecutiveDuplicates(array);

// : Then
System.out.println(Arrays.toString(actual));

• Sample Output

[aba, baa, bab, bba, zzz, bba, aba, bbb];

String[] packConsecutiveDuplicates(String[] array)

• Description
  • Given an array of char objects, return an array of Strings with consecutive duplicates placed in an array.

Example 1

• Sample Script

// : Given
String[] array = {"a", "a", "a", "a", "b", "c", "c", "a", "a", "d"};

// : When
String[] actual = StringArrayUtils.packConsecutiveDuplicates(array);

// : Then
System.out.println(Arrays.toString(actual));

• Sample Output

[aaa, b, cc, aa, d, eee];

Example 2

• Sample Script

// : Given
String[] array = {"t", "t", "q", "a", "a", "a", "b", "c", "c", "a", "a", "d", "e", "e", "e"}; 

// : When
String[] actual = StringArrayUtils.packConsecutiveDuplicates(array);

// : Then
System.out.println(Arrays.toString(actual));

• Sample Output

[tt, q, aaa, b, cc, aa, d, eee];

Example 3

• Sample Script

// : Given
String[] array = {"m", "o", "o", "n", "m", "a", "n"}

// : When
String[] actual = StringArrayUtils.packConsecutiveDuplicates(array);

// : Then
System.out.println(Arrays.toString(actual));

• Sample Output

[m, oo, n, m, a, n];

String[] removeValues(String[] array, String valueToRemove)

• Description
  • Given an array of String objects named array and a String object named valueToRemove
    create and return an array containing identical contents excluding objects whose value is equivalent to valueToRemove. Ensure that the length of the newly created array has been resized based on the removal of the undesired elements.

Example 1

• Sample Script

  // : Given
  String[] array = {"aba", "aba", "baa", "bab", "bba", "bba", "bba", "bba", "bbb", "bbb"};
  
  // : When
  String[] actual = StringArrayUtils.removeValues(array, "aba");
  
  // : Then
  System.out.println(Arrays.toString(actual));
  

• Sample Output

  [baa, bab, bba, bba, bba, bba, bbb, bbb};
  

Example 2

• Sample Script

  // : Given
  String[] array = {"aba", "aba", "baa", "bab", "bba", "bba", "bba", "bba", "bbb", "bbb"};
  
  // : When
  String[] actual = StringArrayUtils.removeValues(array, "bba");
  
  // : Then
  System.out.println(Arrays.toString(actual));
  

• Sample Output

  [aba, aba, baa, bab, bbb, bbb];
  

Example 3

• Sample Script

  // : Given
  String[] array = {"aba", "aba", "baa", "bab", "bba", "bba", "bba", "bba", "bbb", "bbb"};
  
  // : When
  String[] actual = StringArrayUtils.removeValues(array, "bbb");
  
  // : Then
  System.out.println(Arrays.toString(actual));
  

• Sample Output

  [aba, aba, baa, bab, bba, bba, bba, bba];