seprating number from variables

[Ahmed Basheer]

Hi All,
I have array of strings and have a need to seprate the variables from numbers. Is there a cleaner way of doing it in java. I know I can attempt to do an operation on every string and if operation results in exception that it is a variable otherwise a number.Please suggest a better way.

e.g array[0]= "1" , array[1]= "xyz" , array[2]= "1.9" , array[3]= "abc"

I need array_of_variables[]= {"xyz","abc"};
array_of_numbers[]={"1","1.9"}

Thanks for you suggestions in advance.

[Darin Niard]

if (s[i].matches("^[0-9.]+$"))
   // it's a number

If you don't know regex, I'll break it down for you. ^[0-9.]+$ basically means that from start (^) to finish ($), this string only has the numbers 0 through 9 or a period in it ([0-9.]), and at least one (+) of these.

Edit: If you want to include negative numbers, then put a - inside the brackets. Or, if you want to be more precise use ^-{0,1}[0-9.]+$
[ June 23, 2004: Message edited by: Darin Niard ]

[sever oon]

If possible, don't store the information as String objects in the first place. A String is a very, very loosely typed way to keep information...think about it, what information can any object store that can't be stored in a String?

Instead, use Integer objects to keep the numbers (or Double, or whatever level of precision you require...or simply use primitives) and create a new class Variable to represent the variables. That way, you can do neat-o things like:

public class Variable
{
  private Double value;
 
  public boolean isUnset() {
    return value == null;
  }
 
  public Double getValue() {
    return isUnset()? 0 : value.doubleValue();
  }
 
  public void setValue( double v ) {
    value = new Double( v );
  }
 
  public void unset() {
    value = null;
  }
}

Now you can have a variable object that actually is settable to a value. If you decide you want your numbers to be full-fledged objects instead of primitives, then just change all the getter/setter above to deal directly with Double objects instead of double primitives.

sev

[Yogesh Kodgule]

hi Darin!

I read ur post here and u mentioned something about "regex". I understood what u explained here.
I was totally unaware of this thing in java and am very much excited to know more and more about any such things in java.

Can u please refer me to any Link where I can study and understand such things.
Thanks in advance,

Yogesh Kodgule

[Ahmed Basheer]

All,


I think doing it by regex works only in newer version of java, not in Jdk1.3.1. But thanks for suggestions. Going by the Sever suggestion I don't quite understand how I can choose which variables to put in variable object and which ones are absolute values. Sever could you please give me some examples here?

Thanks for you suggestions.
-A

[Darin Niard]

Yogesh, I love regex. It's used a lot in perl, which was my first language, so I find myself using it often (probably too often) in Java. The API has a decent list of regex constructs.

[Yogesh Kodgule]

Thanks Darin!
Thanks for opening a new door of java API for me.
You love regex and i love java....ultimately both feel satisfied.

thanks to Ahmed too ...as he posed the question and things came this way.
And the obvious thanks to the whole Java Community, who make my Java Coding experience as smoother as possible.

Best regards,
Yogesh

[Ivan Jouikov]

Ahmed? Parwiz is that you?

[Max Habibi]

Hi Ahmed,

Welcome to the ranch, and I'm glad you got your question answered

I wanted to tell you that we require members to adhere to a naming policy. That is, a first name followed by a last name, and it should not be a name I recognize, so Don Juan is out. As a matter of fact, we love to encourage member to use their real names. Please modify your name accordingly.

Thanks,
M