ZCW-Arrays-StringArrayUtilities-BlueJ/StringArrayUtils.java

import java.util.*;
/**
 * Created by leon on 1/29/18.
 */
public class StringArrayUtils {
    /**
     * @param array array of String objects
     * @return first element of specified array
     */ // TODO
    public static String getFirstElement(String[] array) {
        return array[0];
    }

    /**
     * @param array array of String objects
     * @return second element in specified array
     */
    public static String getSecondElement(String[] array) {
        return array[1];
    }

    /**
     * @param array array of String objects
     * @return last element in specified array
     */ // TODO
    public static String getLastElement(String[] array) {
        return array[array.length - 1];
    }

    /**
     * @param array array of String objects
     * @return second to last element in specified array
     */ // TODO
    public static String getSecondToLastElement(String[] array) {
        return array[array.length - 2];
    }

    /*
     * @param array array of String objects
     * @param value value to check array for
     * @return true if the array contains the specified `value`
     */ // TODO
    public static boolean contains(String[] array, String value) {
        boolean result = false;
        for (String val : array) {
            if (val.equals(value)) result = true;
        }
        return result;
    }

    /**
     * @param array of String objects
     * @return an array with identical contents in reverse order
     */ // TODO
    public static String[] reverse(String[] array) {
        String[] reverseArray = new String[array.length];
        int j = 0;
        for (int i = array.length - 1; i >= 0; i--) {
            reverseArray[j] = array[i];
            j++;
        }
        return reverseArray;
    }

    /**
     * @param array array of String objects
     * @return true if the order of the array is the same backwards and forwards
     */ // TODO
    public static boolean isPalindromic(String[] array) {
        boolean result = true;
        String[] revArr = new String[array.length];

        int j = 0;
        for (int i = array.length - 1; i >= 0; i--)  {
            revArr[j] = array[i];
            j++;
        }

        for (int i = 0; i < array.length - 1; i++) {
            if (!(array[i].equals(revArr[i]))) result = false;
        }

        return result;
    }

    /**
     * @param array array of String objects
     * @return true if each letter in the alphabet has been used in the array
     */ // TODO
    public static boolean isPangramic(String[] array) {
        String alpha = "abcdefghijklmnopqrstuvwxyz";

        for (int i = 0; i < array.length; i++) {
            String word = array[i];
            for (int j = 0; j < word.length(); j++) {
                String letter = Character.toString(word.charAt(j)).toLowerCase();
                if (alpha.indexOf(letter) != -1) {
                    alpha = alpha.replace(letter, "");
                }
            }
        }

        boolean result = alpha.length() <= 0;
        return result;
    }

    /**
     * @param array array of String objects
     * @param value value to check array for
     * @return number of occurrences the specified `value` has occurred
     */ // TODO
    public static int getNumberOfOccurrences(String[] array, String value) {
        int result = 0;
        for (String val : array) {
            if (val.equals(value)) result += 1;
        }
        return result;
    }

    /**
     * @param array         array of String objects
     * @param valueToRemove value to remove from array
     * @return array with identical contents excluding values of `value`
     */ // TODO
    public static String[] removeValue(String[] array, String valueToRemove) {
        int count = 0;
        for (int i = 0; i < array.length; i++) {
            if(array[i].equals(valueToRemove)) count++;
        }

        String[] newArr = new String[array.length - count];

        int j = 0;
        for (int i = 0; i < array.length; i++) {
            if (!array[i].equals(valueToRemove)) {
                newArr[j] = array[i];
                j++;
            }
        }

        return newArr;
    }

    /**
     * @param array array of chars
     * @return array of Strings with consecutive duplicates removes
     */ // TODO
    public static String[] removeConsecutiveDuplicates(String[] array) {
        int count = 0;
        for (int i = 0; i < array.length - 1; i++) {
            if (array[i].equals(array[i + 1])) count++;
        }

        String[] newArr = new String[array.length - count];
        newArr[newArr.length - 1] = array[array.length - 1];
        int j = 0;

        for (int i = 0; i < array.length - 1; i++) {
            if (!array[i].equals(array[i + 1])) {
                newArr[j] = array[i];
                j++;
            }
        }

        return newArr;
    }

    /**
     * @param array array of chars
     * @return array of Strings with each consecutive duplicate occurrence concatenated as a single string in an array of Strings
     */ // TODO
    public static String[] packConsecutiveDuplicates(String[] array) {
        int count = 1;

        for (int i = 0; i < array.length - 1; i++) {
            System.out.println(!array[i].equals(array[i + 1]));
            if (!array[i].equals(array[i + 1])) count++;
        }

        String[] newArr = new String[count];

        StringBuilder temp = new StringBuilder();
        for (int i = array.length - 1; i >= 0; i--) {
            if (array[i].equals(array[i - 1])) {
                temp.append(array[i]);
            } else {
                temp.append(array[i]);
                newArr[newArr.length - 1] = temp.toString();
                temp = new StringBuilder();
                break;
            }
        }

        int j = 0;
        for (int i = 0; i < array.length - 1; i++) {
            if (array[i].equals(array[i + 1])) {
                temp.append(array[i]);
            } else {
                temp.append(array[i]);
                newArr[j] = temp.toString();
                temp = new StringBuilder();
                j++;
            }
        }

        System.out.println(Arrays.toString(newArr));
        return newArr;
    }
}