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) {
        String result = "";

        result += array[0];

        return result ;
    }

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

        result += array[1];

        return result ;

    }

    /**
     * @param array array of String objects
     * @return last element in specified array
     */ // TODO
    public static String getLastElement(String[] array) {
        String result = "";

        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) {
        String result = "";

        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 x = false;
        for (String i : array){

            if (i == value){

                x = true; 

            }
        }

        return x;
    }

    /**
     * @param array of String objects
     * @return an array with identical contents in reverse order
     */ // TODO
    public static String[] reverse(String[] array) {
        String order;

        for (int x = 0; x < array.length/2; x++){
            order = array[x];

            array[x] = array[array.length -x -1];
            array[array.length -x -1] = order;

        }
        return array;
    }

    /**
     * @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 rev = false;
        for (int x = 0; x < array.length/2; x++){

            if (array[x] == array[array.length -x -1]){

                rev = true;

            }

        }
        return rev;
    }

    /**
     * @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) {
        boolean every = false;
        StringBuilder build = new StringBuilder();

        for(String s: array){
            build.append(s);
        }
        String ofArr = "";
        ofArr = build.toString();
        for (char x = 'A'; x < 'Z'; x++){
            if ((ofArr.indexOf(x) <0) && (ofArr.indexOf((char) (x + 32)) <0)){
                every =false;
            }
            else{  every = true;

            }

        }
        return every;

    }

    /**
     * @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 occur = 0;

        for (int x = 0; x < array.length; x++){

            if (value.equals(array[x])){
                occur++;
            }

        }

        return occur;
    }

    /**
     * @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 place = 0;
        int count = getNumberOfOccurrences(array , valueToRemove);
        String[] newArr = new String [array.length - count];

        for (int x = 0; x < array.length; x++){
            if (array[x] != valueToRemove){
                newArr[place] = array[x];

                place++;
            }

        }

        return newArr;
    }

    /**
     * @param array array of chars
     * @return array of Strings with consecutive duplicates removes
     */ // TODO
    public static String[] removeConsecutiveDuplicates(String[] array) {
        int newArrIndex= 0;

        String[] newArr = new String[array.length];
        newArr[newArrIndex] = array[0];
        newArrIndex++;

        for (int x = 1; x < array.length; x++){
            if (!array[x].equals(newArr[newArrIndex - 1])){

                newArr[newArrIndex]= array[x]; 

                newArrIndex++;
            }

        }
        String[] newArr2 = new String [newArrIndex];
        System.arraycopy(newArr, 0 , newArr2,  0, newArrIndex);

        return newArr2;

        
    }

    /**
     * @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) {
        StringBuilder dups = new StringBuilder(array[0]);

        String[] newArr = new String[array.length-count(array)];
        int adding = 0;

        for (int x = 1; x < array.length; x++){
            if (array[x-1].equals(array[x])){
                dups.append(array[x]);
            }
            else {
                newArr[adding] = dups.toString();
                dups.setLength(0);
                dups.append(array[x]);
                adding++;

            }
        }

        newArr[adding] = dups.toString();
        return newArr;
    }

    public static int count(String[] array){
        int count = 0;

        for (int x = 1; x < array.length; x++){
            if (array[x-1].equals(array[x])){

                count++;    
            }

        }
        
        return count;
    }

}