CR-MicroLabs-JavaFundamentals-DanDoBetterDrills/StringUtilities.java

 import java.util.*;

/**
 * Created by dan on 6/14/17.
 */
public class StringUtilities {
    /**
     * @return `Hello World` as a string
     */
    public static String getHelloWorld() {
        return "Hello World";
    }

    /**
     * @param firstSegment a string to be added to
     * @param secondSegment a string to add
     * @return the concatenation of two strings, `firstSegment`, and `secondSegment`
     */
    public static String concatenation(String firstSegment, String secondSegment){
        return firstSegment + secondSegment;
    }

    /**
     * @param firstSegment a string to be added to
     * @param secondSegment a string to add
     * @return the concatenation of an integer, `firstSegment`, and a String, `secondSegment`
     */
    public static String concatenation(int firstSegment, String secondSegment){
        return firstSegment + secondSegment;
    }

    /**
     * @param input a string to be manipulated
     * @return the first 3 characters of `input`
     */
    public static String getPrefix(String input){
        return input.substring(0, 3);
    }

    /**
     * @param input a string to be manipulated
     * @return the last 3 characters of `input`
     */
    public static String getSuffix(String input){
        return input.substring(2, 5);
    }

    /**
     * @param inputValue the value to be compared
     * @param comparableValue the value to be compared against
     * @return the equivalence of two strings, `inputValue` and `comparableValue`
     */
    public static Boolean compareTwoStrings(String inputValue, String comparableValue){
        return inputValue.equals(comparableValue);
    }

    /**
     * @param inputValue the value input from user
     * @return the middle character of `inputValue`
     */
    public static Character getMiddleCharacter(String inputValue){
        return inputValue.charAt((inputValue.length()-1)/2);
    }

    /**
     * @param spaceDelimitedString a string, representative of a sentence, containing spaces
     * @return the first sequence of characters
     */
    public static String getFirstWord(String spaceDelimitedString){
        return (spaceDelimitedString + " ").split(" ")[0];
    }

    /**
     * @param spaceDelimitedString a string delimited by spaces
     * @return the second word of a string delimited by spaces.
     */
    public static String getSecondWord(String spaceDelimitedString){
        return (spaceDelimitedString + " ").split(" ")[1];
    }

    /**
     * @param stringToReverse
     * @return an identical string with characters in reverse order.
     */
    public static String reverse(String stringToReverse){
        StringBuilder newInput = new StringBuilder();
        newInput.append(stringToReverse);
        newInput.reverse();
        
        return newInput.toString();
    }
}