ints and operators?

[d00d]

hello,

I had a quick, and hopefully easy question.

I have a variable with a string in it, like

private String bla = "5+3*4";

what i was wondering... i want to take all the ints and put them in an int array, and all the operators and put them in an operator array.

something like that

[sjalle]

Here goes:

import java.util.*;

public class Expressionator {
  ArrayList ops=new ArrayList();
  ArrayList ints=new ArrayList();
  // you might want to include brackets & parentheses here
  String opers="+-*/"; 
  public Expressionator(String s) {
    StringTokenizer st=new StringTokenizer(s,opers,true);
    while (st.hasMoreElements()) {
      String whatzit=(String)st.nextElement();
      if (opers.indexOf(whatzit)>=0) {
        ops.add(whatzit);
      } else {
        ints.add(whatzit);
      }
    }
    // if you insist on arrays then
    int [] intArr=new int[ints.size()];
    String [] operArr=new String [ops.size()];
    for (int i=0;i<ints.size();i++) {
      intArr[i]=Integer.parseInt((String)ints.get(i));
    }
    for (int i=0;i<ops.size();i++) {
      operArr[i]=(String)ops.get(i);
    }
    System.out.println("The expression:"+s);
    System.out.println("Integers:");
    for (int i=0;i<intArr.length;i++) {
      System.out.println(intArr[i]);
    }
    System.out.println("Operators:");
    for (int i=0;i<operArr.length;i++) {
      System.out.println(operArr[i]);
    }

  }
  public static void main(String[] args) {
    String s="";
    for (int i=0;i<args.length;i++) {
      s+=args[i];
    }
    Expressionator exp = new Expressionator(s);
  }

}

[lionelBadiou]

Hi all,

Nice job sjalle (as usal). You have been quicker than me
May I mention yet :

StringTokenizer is a legacy class that is retained for compatibility reasons although its use is discouraged in new code. It is recommended that anyone seeking this functionality use the split method of String or the java.util.regex package instead.

Details are here

Best regards,

[sjalle]

I know... I was told this as early as -96 I think, so its
really just a bad habit...

[lionelBadiou]

Hi again sjalle,

Anyway, I obviously mentioned it for d00d, not for you

[d00d]

thanks for the help