Extract the elements of string in java

**Ash maker** · 13-01-2010

Hello,
I have a string long enough my aim is to extract from string the elements that constitute it, but it is a little more special.

(Other receivables + Accounts receivable)/5.25* ARRESTED IN NV + P Preliminary

the desired result after insertion into the vector cad vector content:
will be as follows

Vector v =[(, Other debtors + Accounts receivable,),/,5.25, *, STANDING IN NV, +, preliminary expenses]

It has a function to do this treatment.

**opaper** · 13-01-2010

Hi,
The best is probably construct a parser for it, I advise you to use
Antlr (nothing to do with Ant). Basically you give him your "grammar": a variable is an alphanumeric string, an addition is: Variable '+' variable. Hope this will help you. If you have any more problems then do post back.

**MindSpace** · 13-01-2010

Hello,
Even simpler, with RegExp and method String.split. You can try the following line of code. This will make your code simpler.

Code:

String[] res = s.split("\\+|\\*|/");

I think this is the correct choice for your situation.

**Ash maker** · 13-01-2010

Hello
I tried with splits, though I am not sure that this works correctly and is this the correct way to do it?

String s ="(Other receivables + Accounts receivable) / 5.25 * ARRESTED IN NV + Shipping preliminary";
String[] res = s.split("\\+|\\*|/");
System.out.print(res);

the result is the following:

[(, Other Receivables, Accounts receivable,),5.25, STANDING IN NV, preliminary expenses]

It Does not operators +,*,/ what is obvious, but my objective is to insert the same operators +,*,/ but respecting their orders in the chain.

**kelfro** · 13-01-2010

Hello,
The solution is to take the problem in reverse: instead of cutting the string according to certain criteria, it would be wise to find items in the chain.
I understand that I see 3 things to look for
1) Mathematical symbols: (+*/-)
2) Figures
3) The strings (short, everything except the above).
What I translate into this:

Code:

	Final String symbols = "[+-/*()]"; / / A character from the following: + - * / ()
	Final String numbers = "\\d + (\\.\\d *)? "; / / Numbers: at least one number, possibly followed by '. " and optional data
	Final String string = "[^+-/*()\\d] + "; / / A string: All who are no numbers or symbols

Then just look for these items:

Code:

	String input = "(Other receivables + Accounts receivable) / 5.25 * ARRESTED IN NV + Shipping preliminary";

Pattern pattern = Pattern.compiles("("+ + symbols")|("numbers + +")|("+ + strings")");
Matcher matcher = pattern.matcher(input);
	while (matcher.find()) {
		System.out.System.out.println("Found: [" + Matcher.group() + "]");
	}

Now if your need is more complex it will probably define a grammar and use a parser generator such as Javac.

**Ash maker** · 13-01-2010

Hello,
I implemented you code and here is the result

Code:

Final String symbols = "[+-/*()]"; / / A character from the following: + - * / ()
	Final String numbers = "\\d + (\\.\\d *)? "; / / Numbers: at least one number, possibly followed by '. " and optional data
	Final String string = "[^+-/*()\\d] + "; / / A string: All who are no numbers or symbols
String input = "(Other receivables + Accounts receivable) / 5.25 * ARRESTED IN NV + Shipping preliminary";

Pattern pattern = Pattern.compiles("("+ + symbols")|("numbers + +")|("+ + strings")");
Matcher matcher = pattern.matcher(input);
	while (matcher.find()) {
		System.out.System.out.println("Found: [" + Matcher.group() + "]");
	}