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Java Java Objects Creating the MVP Conference Registration Assistant

Johan Herö
Johan Herö
562 Points

I cant figuer out why it dosent work. Its not beutiful but it I think it should work;/

Any Ideas guys?

ConferenceRegistrationAssistant.java
public class ConferenceRegistrationAssistant {

  /**
   * Assists in guiding people to the proper line based on their last name.
   *
   * @param lastName The person's last name
   * @return The line number based on the first letter of lastName
   */
  public int getLineNumberFor(String lastName) {
    int lineNumber = 0;

    char firstLetter = lastName.charAt(0);

    if(firstLetter == (('a') || ('b') || ('c') || ('d') || ('e') || ('f') || ('g') || ('h') || ('i') || ('j') || ('k') || ('l') || ('m'))) {
      lineNumber = 1;
    }
    else {lineNumber=2;}

    /*
      lineNumber should be set based on the first character of the person's last name
      Line 1 - A thru M
      Line 2 - N thru Z

     */
    return lineNumber;
  }

}
Example.java
public class Example {

  public static void main(String[] args) {
    /*
      IMPORTANT:  You can compare characters using <, >. <=, >= and == just like numbers
     */
    if ('C' < 'D') {
      System.out.println("C comes before D");
    }

    if ('B' > 'A') {
      System.out.println("B comes after A");
    }

    if ('E' >= 'E') {
      System.out.println("E is equal to or comes after E");
    }

    // This code is here for demonstration purposes only...
    ConferenceRegistrationAssistant assistant = new ConferenceRegistrationAssistant();
    /*
      Remember that there are 2 lines.
      Line #1 is for A-M
      Line #2 is for N-Z
     */
    int lineNumber = 0;
    /*
      This should set lineNumber to 2 because
      The last name is Zimmerman which starts with a Z.
      Therefore it is between N-Z
     */
    lineNumber = assistant.getLineNumberFor("Zimmerman");

    /*
      This method call should set lineNumber to 1, because 'A' from "Anderson" is between A-M.
     */
    lineNumber = assistant.getLineNumberFor("Anderson");

    /*
      Likewise Charlie Brown's 'B' is between 'A' and 'M', so lineNumber should be set to 1
     */
    lineNumber = assistant.getLineNumberFor("Brown");
  }

}

1 Answer

Florian Stegemann
seal-mask
.a{fill-rule:evenodd;}techdegree
Florian Stegemann
Full Stack JavaScript Techdegree Student 22,660 Points

Hi, i can see two problems with your if-clause:

First, you can't compare one variable to multiple characters like you tried in your example. If you wanted to compare firstLetter to each character individually, you would have to do it like this:

if(firstLetter == 'a' || firstLetter == 'b' || firstLetter == 'c' /* ... and so on */)

Remember though, that you can also use the greater then and less then operators to compare firstLetter to a range of letters like this:

if(firstLetter >= 'a' && firstLetter <= 'z')

This example reads like if firstLetter is greater or equal than a AND if firstLetter is less or equal than z, which basically checks wether firstLetter is between a and z.

Secondly, keep in mind that Java is case sensitive. That means that a and A are not the same character when doing comparisons.