How do you search through letters in java

Question

I dont believe it was covered in the vids. How can you search string through the alphabet to a limit. for example search a string for a character from a-m

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;
    /*
      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

     */lastName.charAt(0);
    if(lastName <= "M") {
      lineNumber = 1;
    }
      else{lineNumber =2;}


    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");
  }

}

Answer 1 · 2017-03-02T05:21:16Z

March 2, 2017 5:21am

Hi David, your logic is fine, it's just that you have 2 coding issues.

public int getLineNumberFor(String lastName) {
  int lineNumber = 0;
  lastName.charAt(0); // you want to store this value in a char or just use charAt in the conditional check
  if(lastName <= "M") {  // M should be surrounded by single quotes since it is a char value, and you want to compare with the character at the front, not the entire lastName
    lineNumber = 1;
  }
  else {
    lineNumber = 2;
  }
  return lineNumber;
}

I'm going to store the first character in a value, rather than use charAt in the conditional check, just to keep things simple.

public int getLineNumberFor(String lastName) {
  int lineNumber = 0;
  char c = lastName.charAt(0);
  if(c <= 'M') {
    lineNumber = 1;
  }
  else {
    lineNumber = 2;
  }
  return lineNumber;
}

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David Dooley

David Dooley

How do you search through letters in java

1 Answer

Umesh Ravji

Umesh Ravji