Which comes first? The char or the String?

Question

Most of the examples I find in my search for the answer are embedded in complex code. I'm just trying to have a question program know to accept either upper or lower case responses to a two-answer (binary?) question and then to use either answer to proceed to a singular result. I tried an if/else approach before I found character class methods in my book, but it only helps half way with it's examples.

here's the code:

 import java.util.Scanner;
public class MarriageQuiz
{
public static void main(String[] args)
{   
  char isMarried = 'M';
  char isSingle = 'S';
  String marStat;

  System.out.print("Please enter your Marital Status (M or S) >> ");
  marStat = input.nextLine();

     if(marStat.isUppercase(isMarried | isSingle))
     {
        marStat = input.nextLine();
     }
     else if((marStat.isLowercase(isMarried | isSingle)))
     {
        marStat = marStat.toUpperCase(isMarried | isSingle);
     }
     System.out.print("You are " + marStat);
}
}

I thought about using StingBuilder but I still have to identify the string to be edited. — Ryan Martin, Aug 20 '16 at 05:58
What exactly is your Question? Another thing, the logic of your code example does not make sense, the purpose cannot be discerned. — Basil Bourque, Aug 20 '16 at 06:02
If I ask "Please enter your Marital Status" how can I have the program understand that 'M' is the same as 'm' and 'S' is the same as 's'? Then use it for the input for marStat? — Ryan Martin, Aug 20 '16 at 06:04

score 2 · Accepted Answer · answered Aug 20 '16 at 06:15

2

Just convert all input to your expected case (upper or lowercase, you pick one).

No harm done in trying to convert a character to one case that happens to already be in that case. The toUppercase method does not complain when you call it needlessly. So no need to test for case at all.

marStat = marStat.toUppercase() ;
if ( marStat.equals( 'S' ) {
    … do Single stuff
} else if ( marStat.equals( 'M' ) {
    … do Married stuff
} else {
    … handle unexpected input
}

Tip: if running this code a zillion times, consider replacing the use of the char primitive with the Character class to avoid the autoboxing discussed in the Oracle Tutorial.

answered Aug 20 '16 at 06:15

Basil Bourque

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1

Any new coders out there would do well to remember this "pattern" -- you'll use it over and over in your career whenever you're comparing user input to some known string. – MarsAtomic Aug 20 '16 at 06:36
@RyanMartin ??? Make the M & S into what? – Basil Bourque Aug 20 '16 at 06:48
Never-mind. I think you answered my question though. I want to use 'M' or 'S' in my if/else actions I just didn't know how to get it to be recognized regardless of case. – Ryan Martin Aug 20 '16 at 06:56
I don't think I even needed the char of either – Ryan Martin Aug 20 '16 at 07:25

score 0 · Answer 2 · answered Aug 20 '16 at 06:19

isUppercase and isLowercase doesn't work like that at all. And your code makes little sense.

It seems like that you want to compare characters only, but you called nextLine which returns a String. And in the if statements, somehow you are asking for user input again. I don't really know what you're doing here.

I guess you want something like this:

char isMarried = 'M';
char isSingle = 'S';
char marStat;

System.out.print("Please enter your Marital Status (M or S) >> ");
marStat = input.nextLine().charAt(0);

if(marStat == 's' || marStat == 'S')
{
   System.out.println("You are single!");
}
else if(marStat == 'm' || marStat == 'M')
{
   System.out.println("You are married!");
}

I don't think you fully understand how programming works.

Which comes first? The char or the String?

2 Answers2