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Start your free trialPaul Warden
Courses Plus Student 2,372 PointsWhy wont this compile? It is telling me I cannot use the comparison operators
I just don't see anything wrong
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) {
if (lastName.charAt(0) < "N") {
int lineNumber = 1;
}else{
int 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;
}
}
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
Todd Anderson
4,260 PointsAt first glance it looks like you are using double quotes to compare a char in your getLineNumberFor method which should be single quotes in Java. The other thing is that you do not need to create an int. It just wants you to either return 1 or 2... so if... return 1; else return 2;
Good luck.
Martin Zarate
10,723 PointsI re-wrote your function a little bit:
public class ConferenceRegistrationAssistant {
public int getLineNumberFor(String lastName) {
int lineNumber = 0;
// get the first char from the last name
char charLetter = lastName.charAt(0);
// make it a string type
String firstLetter = Character.toString( charLetter );
// create the result variable
// this value will be less than 0 if firstlLetter is lower than "N"
// this value will be greater than 0 if firstlLetter is higher than "N"
// it will return 0 if both strings are equal
int result = firstLetter.compareTo( "N" );
if ( result < 0 ) {
lineNumber = 1;
}
else{
lineNumber = 2;
}
return lineNumber;
}
}
I hope this helps, cheers.
Todd Anderson
4,260 PointsWhy not...
public int getLineNumberFor(String lastName) { if (lastName.charAt(0) < 'N') { return 1; }else{ return 2; } }
Much cleaner and simpler.
Paul Warden
Courses Plus Student 2,372 PointsPaul Warden
Courses Plus Student 2,372 PointsThanks I had such a hard time catching the double quotes that I will likely never miss this particular error again!