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Java Java Objects (Retired) Creating the MVP Comparing Characters

Shubham Modi
Shubham Modi
5,799 Points
Posted by Shubham Modi
Shubham Modi
5,799 Points

I barely understand the question

I have modeled an assistant for a tech conference. Since there are so many attendees, registration is broken up into two lines. Lines are determined by last name, and they will end up in line 1 or line 2. Please help me fix the getLineFor method.

ConferenceRegistrationAssistant.java 
public class ConferenceRegistrationAssistant {

  public int getLineFor(String lastName) {
    /* If the last name is between A thru M send them to line 1
       Otherwise send them to line 2 */
    int line = 0;
    char lastName > 0;
    return line;
  }

}

3 Answers

jcorum
jcorum
71,830 Points
jcorum
jcorum
71,830 Points

Yes, sometimes the questions can be a bit difficult to unravel. What they want, for the returned value, is an int. They want the function to say, given a last name, whether the person should be in line 1 or line 2, so the function has to return either a 1 or a 2:

 public int getLineFor(String lastName) {
    /* If the last name is between A thru M send them to line 1
       Otherwise send them to line 2 */
    int line = 0;
    if (lastName.charAt(0) < 'M') {
      line = 1;
    } else {
      line = 2;
    }
    return line;
  }
Chaz Hall
Chaz Hall
1,970 Points
Chaz Hall
Chaz Hall
1,970 Points

Would:

if (lastName.charAt(0)<'M') just be A-L since you said <'M' and not <= 'M'

?

jcorum
jcorum
71,830 Points
jcorum
jcorum
71,830 Points

Chaz, not sure I understand your question. The charAt() function returns the char at the index specified as a parameter. So charAt(0) returns the first char in a String. (Remember Java indices always start at 0.)

So if the last name is Smith charAt(0) would be 'S'. If the last name were Jones charAt(0) would be 'J'.

The reason you can use the < operator here is because under the hood chars are ints (in fact, their ASCII values). So 'A' (65) is less than 'M' (77).

Chaz Hall
Chaz Hall
1,970 Points
Chaz Hall
Chaz Hall
1,970 Points

I'm sorry I wasn't clear.

A=0 B=1 C=2 D=3 E=4 F=5 G=6 H=7 I=8 J=9 K=10 L=11 M=12

If it's less than M then it would go to line =1. But what if your name is Malfoy? My understanding is that in that code M-Z would go into line 2 unless the code was like this: if(lastName.charAt(0)<='M') //which is the less than or equal to.

I'm just trying to understand if that logic is correct is all :)

jcorum
jcorum
71,830 Points
jcorum
jcorum
71,830 Points

Close. But in ASCII A = 65, B = 66, etc.

Re Malfoy, it says 

if (lastName.charAt(0) < 'M')

Since 'M' (77) is not less than 'M' (77) Malfoy ends up in line 2.