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input help in java

Sat, 26 Mar 2005 09:03:52 -0700

I'm having a problem in my program where I'm trying to allow a user to input a single letter. Unfortunately, there is no such thing as
flav = scan.nextChar() and I was wondering how I can do it. I'm trying to use it for the following switch case:

switch ( flav )
{
case 'c':
kind = COLUMBIAN;
break;
case 'j':
kind = JAVAN;
break;
case 'b':
kind = BRAZILIAN;
break;
case 'm':
kind = MEXICAN;
break;
default:
s = BAD_FLAVOR;
}

Re: input help in java

Sat, 26 Mar 2005 15:23:09 -0700

Take the input in, as a string and then convert it to a char using charAt(), in the string class.

In most cases, it is a good idea to take user input as a string as it gives you an opportunity to make sure it is valid data.

Re: input help in java

Sat, 26 Mar 2005 17:47:27 -0700

I typed in the following code to get the letter of each flavor:

flav = scan.nextLine();
length = flav.length();
for (i = 0; i < length; i++)
{
flavor = flav.charAt(i);

switch (flavor)
{
case ('c'):
kind = coffee.columbian;
System.out.println(kind);
break;

case ('j'):
kind = coffee.javan;
System.out.println(kind);
break;

case ('b'):
kind = coffee.brazilian;
System.out.println(kind);
break;

case ('m'):
kind = coffee.mexican;
System.out.println(kind);
break;

default:
System.out.println("Bad Flavor");
}
}

The problem is that not only does it print out the coffee I want, but it also prints out Bad Flavor and other brands of coffee. What can I do to make it only print out one flavor and not anything else?

Re: input help in java

Sat, 26 Mar 2005 17:54:46 -0700

: I typed in the following code to get the letter of each flavor:
:
: flav = scan.nextLine();
: length = flav.length();
: for (i = 0; i < length; i++)
: {
: flavor = flav.charAt(i);
:
: switch (flavor)
: {
: case ('c'):
: kind = coffee.columbian;
: System.out.println(kind);
: break;
:
: case ('j'):
: kind = coffee.javan;
: System.out.println(kind);
: break;
:
: case ('b'):
: kind = coffee.brazilian;
: System.out.println(kind);
: break;
:
: case ('m'):
: kind = coffee.mexican;
: System.out.println(kind);
: break;
:
: default:
: System.out.println("Bad Flavor");
: }
: }
:
: The problem is that not only does it print out the coffee I want, but it also prints out Bad Flavor and other brands of coffee. What can I do to make it only print out one flavor and not anything else?
:

What is scan an object of? Are you inputting a single character? If yes, it looks like scan takes in the char and the end of line marker, so its length is 2, so it loops twice. That is just a guess since i don't know what scan is. You can check it, by printing out length. There are classes that handle stuff liek this easily, like BufferedReader.

Re: input help in java

Sat, 26 Mar 2005 18:16:35 -0700

All I wanted was the first letter in the name of the flavor. I used scan as part of the Scanner class where I let a user input the the name of the brand and then the switch case uses the first letter of that brand. All I need is just find something that would only accept the first letter and nothing else.

Re: input help in java

Thu, 31 Mar 2005 20:43:20 -0700

: All I wanted was the first letter in the name of the flavor. I used scan as part of the Scanner class where I let a user input the the name of the brand and then the switch case uses the first letter of that brand. All I need is just find something that would only accept the first letter and nothing else.

To get just one character, use scan.next().charAt(0).

Re: input help in java

Fri, 01 Apr 2005 09:36:07 -0700

: : All I wanted was the first letter in the name of the flavor. I used scan as part of the Scanner class where I let a user input the the name of the brand and then the switch case uses the first letter of that brand. All I need is just find something that would only accept the first letter and nothing else.
:
: To get just one character, use scan.next().charAt(0).
:
Hello;

You need to probably do some input checking maybe something like this...

class GetFlavor{

public static void main(String [] args){
String input = args[0].toLowerCase();
    char[] inpcheck = input.toCharArray();

if (inpcheck.length > 1){
        System.out.println("You must enter only the first letter of your coffee flavor");
        
}
    else{
        
        chosenFlavor(input.charAt(0));
    }

}
public static void chosenFlavor(char flavor){
    String kind = null;
    
    switch (flavor) 
{ 
case ('c'): 
kind = "coffee.columbian"; 
System.out.println(kind); 
break; 

case ('j'): 
kind = "coffee.javan"; 
System.out.println(kind); 
break; 

case ('b'): 
kind = "coffee.brazilian"; 
System.out.println(kind); 
break; 

case ('m'): 
kind = "coffee.mexican"; 
System.out.println(kind); 
break; 

default: 
System.out.println("Bad Flavor"); 
} 

}

}

I think this will run.
Hope this helps.
let us know if you need any additional help.

Ken