Could you help me with these I'm a bit confuse

Question

Give me a hand plz

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;
    if  (lastName.charAt(0) == 'a'  || 'b'  || 'c'  || 'd'  || 'e'  || 'f'  || 'g' || 'h' || 'i'  || 'j'  || 'k'  || 'l'  || 'm'){
     lineNumber +=;
    }

    else (lastName.charAt(0) == 'n'  || 'o'  || 'p'  || 'q'  || 'r'  || 's'  || 't' || 'u' || 'v'  || 'w'  || 'x'  || 'y'  || 'z'){ 
    lineNumber + 1 
  }

}

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");
  }

}

Answer 1 · 2017-11-06T07:02:38Z

November 6, 2017 7:02am

Hi there! thankfully with characters of letters we can use comparative logic! It would be awfully repetitive if we had to type out an or || for every single condition. We also should normalize the input with a .toLowerCase() method (i am not sure if the challenge calls for this however it is good practice). This would look as follows:

  public int getLineNumberFor(String lastName) {
    int lineNumber = 0;

    if(lastName.toLowerCase().charAt(0) < 'n') { //Here we can simply check that its less than n (a-m)
      lineNumber = 1;                         //we also stack the .toLowerCase to normalize input
    } else{ //otherwise, return 2
     lineNumber = 2; 
    }
    return lineNumber;
  }

Also just as a side note, this line of code that you have here:

    else (lastName.charAt(0) == 'n'  || 'o'  || 'p'  || 'q'  || 'r'  || 's'  || 't' || 'u' || 'v'  || 'w'  || 'x'  || 'y'  || 'z'){ 
   //For this code to work you would need to use "else if"
    lineNumber + 1 
  }

If the condition has logical comparison you want to use "else if" rather than "else". "else" doesn't take any arguments to compare, it is simply the condition that will execute if nothing else matches. Above we used

else{ 
         lineNumber = 2; 
    }

because in terms of this program, if it isnt a-m it is n-z.

Hope this helps! happy coding

Welcome to the Treehouse Community

Looking to learn something new?

Juan Prieto

Juan Prieto

Could you help me with these I'm a bit confuse

1 Answer

michaelcodes

michaelcodes

Juan Prieto

Juan Prieto

michaelcodes

michaelcodes