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Java Java Objects Creating the MVP Conference Registration Assistant

Hyun Yoo
Hyun Yoo
975 Points

Why is this code not working?

I deleted the line: int lineNumber = 0; Is that wrong? Please help me. Thank you.

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) {
    char getFirstLetter = lastName.charAt(0);
    if (getFirstLetter => 'A' && getFirstLetter <= '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");
  }

}

2 Answers

andren
andren
28,558 Points

Your code is pretty much there, there are only two issues:

  1. Yes removing the line int lineNumber = 0; is wrong. That line creates the lineNumber variable, you can't assign a value to a variable without creating it first, which is what you end up doing in your current code.
  2. In your first if statement condition you have written => instead of >=, the order of the symbols matter.

If you restore that line you removed and replace => with >= like this:

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 getFirstLetter = lastName.charAt(0);
    if (getFirstLetter >= 'A' && getFirstLetter <= '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;
  }
}

Then your code will work.

Hyun Yoo
Hyun Yoo
975 Points

Thank you.