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Start your free trialThomas Verst
725 PointsCan't solve
I wasn't able to solve the task. Could someone help me please? Fix the getLineNumberFor method to return a 1 if the first character of lastName is between A and M or else return 2 if it is between N and Z.
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
*/
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");
}
}
3 Answers
Ian Taylor
Courses Plus Student 1,420 PointsUsing those two top methods I get this error: onferenceRegistrationAssistant.java:11: error: bad operand types for binary operator '<=' ./ConferenceRegistrationAssistant.java:11: error: bad operand types for binary operator '<=' if(lastName <= 'M' && lastName >= 'A') { ^ first type: String second type: char ./ConferenceRegistrationAssistant.java:11: error: bad operand types for binary operator '>=' if(lastName <= 'M' && lastName >= 'A') { ^ If I use the compareTo() method it still doesn't work. I have even modified it with no luck.
lineNumber = lastName.charAt(0).compareTo('M); return lineNumber;
Davis Hubbard
19,896 PointsThis problem can be solved using a simple if-else on a conditional similar to what is seen in the examples in Example.java. Something along the lines of
if(lastName <= 'M' && lastName >= 'A') {
lineNumber = 1;
}
with a complimentary else if to test N-Z should work well.
Thomas Verst
725 Points public int getLineNumberFor(String lastName) {
int lineNumber = 0;
if(lastName <= 'M' && lastName >= 'A') {
lineNumber = 1;
} else {
lineNumber = 2;
}
I got 2 compiler errors now. ./ConferenceRegistrationAssistant.java:11: error: bad operand types for binary operator '<=' if (lastName <= 'M' && lastName >= 'A') { ^ first type: String second type: char ./ConferenceRegistrationAssistant.java:11: error: bad operand types for binary operator '>=' if (lastName <= 'M' && lastName >= 'A') { ^ first type: String second type: char Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 2 errors
Davis Hubbard
19,896 PointsTry using the string method .CompareTo(). It takes a string to compare against as the argument, and returns an integer which tells how they compare. 0 is returned if they are equal, a negative value if the string is less than the argument, or a positive value if it is greater. Sorry for the confusion. Additional docs can be found here
Ian Taylor
Courses Plus Student 1,420 PointsIan Taylor
Courses Plus Student 1,420 PointsOk I managed to get it working by
if (lastName.charAt(0) <= 'M'){ lineNumber = 1; }