Regular Expression Confusion

[Samar Bir]

Hi Everyone,

I am trying to understand Scanner. Here is a example of javacodegeeks. The source code is

import java.util.* ;

public class ScannerTokenizingText  {
	public static void main(String[] args){
		String text = "4231  , Java Programming, 1000.00";
		
		Scanner scanner = new Scanner(text).useDelimiter("\\s*,\\s*"); //1
		int checkNumber = scanner.nextInt();
		String description = scanner.next();
		float amount = scanner.nextFloat();
		System.out.printf("/***** Tokenizing Text *****/\n\n");
		
		System.out.printf("String to tokenize: %s\n", text);
		System.out.printf("checkNumber: %d\n", checkNumber);
		System.out.printf("description: %s\n", description);
		System.out.printf("amount: %f", amount);

	}
}

On point-1, it is using delimiter a regular expression. Does this regular expresson mean, any number of spaces followed by the coma?
Kindly help.
Thanks,
Samarbir

[Junilu Lacar]

Welcome to the Ranch!

You can find a number of Java regex testers that can be used to help you test.

[Samar Bir]

Dear Junilu,

Thanks for reverting back. What i understood from using the testers, this regex means, a comma following or preceded by a space. zero or one occurance.
Do let me know, if i am getting it correct?

Thanks,
Samarbir

[Junilu Lacar]

It looks reasonable to assume so but honestly, I'd have to go and test it myself. Since it looks like you've already done that then you're better off trusting the results of your tests than my opinion.