ZCW-Arrays-StringArrayUtilities-BlueJ/StringArrayUtils.java

import java.util.Arrays;
/**
 * 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 containsString = false;
        for (String element : array)
            if(element.equals(value)){
                containsString = true;  
                break;
            }
        return containsString;
    }

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

    /**
     * @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) {
        String[] reverseString = reverse(array);
        boolean isTrue = false;
        if(Arrays.equals(reverseString, array)){
            return true;
        }
        return isTrue;
    }

    /**
     * @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){
        char [] alphabet = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
        boolean containsEveryLetter = true;
        for(char letter:alphabet){
            if(arrayContainsLetter(array,letter)==false){
                containsEveryLetter = false;
                break;
            }
        }
        return containsEveryLetter;
    }

    public static boolean arrayContainsLetter(String[] array, char letter){
        boolean containsLetter = false;
        for(String string : array){
            if(stringContainsLetter(string.toLowerCase(),letter)){
                containsLetter = true;
                break;
            }
        }
        return containsLetter;
    }

    public static boolean stringContainsLetter(String string, char letter){
        boolean containsLetter = false;
        for(int i = 0; i < string.length(); i++){
            if (string.charAt(i)==letter){
                containsLetter = true;
                break;
            }
        }
        return containsLetter;
    }

    /**
     * @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 counter = 0;
        for (String element : array){
            if(element.equals(value)){
                counter += 1;
            }
        }
        return counter;
    }

    /**
     * @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 lengthOfNewArray = array.length-getNumberOfOccurrences(array,valueToRemove);
        String[] newArray = new String[lengthOfNewArray];
        int index = 0;
        for(String element : array){           
            if(element != valueToRemove){
                newArray[index] = element;
                index += 1;
            }
        }
        return newArray;
    }

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

    public static int countDuplicates(String[] array){
        int duplicates = 0;
        for (int i =1; i< array.length; i++){
            if(array[i].equals(array[i-1])){
                duplicates++;
            }
        }
        return duplicates;
    }

    /**
     * @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 newArrayLength = array.length-countDuplicates(array);
        String [] newArray = new String [newArrayLength];
        
        StringBuilder tempString = new StringBuilder(array[0]);
        int index = 0;
        
        for (int i = 1; i< array.length; i++){
           
           if(array[i].equals(array[i-1])){
               tempString.append(array[i]);
            }else{
                newArray[index] = tempString.toString();
                index++;
                tempString.delete(0,tempString.length());
                tempString.append(array[i]);
            }
        } 
        newArray[index] = tempString.toString();
        return newArray;
    }
    

}