CR-MicroLabs-JavaFundamentals-DanDoBetterDrills/StringUtilities.java

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

    /**
     * @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){
      String joined = firstSegment.concat(secondSegment);
        return joined;
    }

    /**
     * @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){
      String joined = new String();
      joined += "" + firstSegment;
      joined += secondSegment;
      return joined;
    }

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

      String prefix = new String();
      prefix = input.substring(0,3);
        return prefix;
    }

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

    /**
     * @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){
        char middle;
        int pos, len;
        char ch[] = inputValue.toCharArray();

        len = ch.length;
        if(ch.length%2 == 0){
            pos = len/2 - 1;
        } else{
            pos = len/2;
        }

        middle = ch[pos];
        return middle;
    }

    /**
     * @param spaceDelimitedString a string, representative of a sentence, containing spaces
     * @return the first sequence of characters
     */
    public static String getFirstWord(String spaceDelimitedString){

        int index = spaceDelimitedString.indexOf(' ');
        String word = spaceDelimitedString.substring(0,index);
        return word;
    }

    /**
     * @param spaceDelimitedString a string delimited by spaces
     * @return the second word of a string delimited by spaces.
     */
    public static String getSecondWord(String spaceDelimitedString){
        
        String str = spaceDelimitedString;
        int index = str.indexOf(' ');
        String word = new String();
        
        if(str.indexOf(' ', index+1)!=-1){
            int index2 = str.indexOf(' ', index+1);
            word = str.substring(index+1,index2);
        }else if(str.indexOf(' ', index+1)==-1){
            word = str.substring(index+1, str.length());
        }else{
            word = str.substring(0,index);
        }
        return word;
    }

    /**
     * @param stringToReverse
     * @return an identical string with characters in reverse order.
     */
    public static String reverse(String stringToReverse){

        char ch[] = stringToReverse.toCharArray();
        String reversed = new String();

        for(int i=(ch.length)-1; i>=0; i--){
          reversed += ch[i];
        }
        
        return reversed;
    }
}