Question

I am a beginner of Java Programming language.

When I input (1,2) into the console (brackets included), how can I write the code to extract the first and the second number using RegEx?

If there is no such expression to extract the first/second number within the brackets, I will have to change the way of inputing coordinates to x,y without the brackets and that should be a lot easier to extract numbers to be used.

Answer 1

Try this code:

public static void main(String[] args) {
    String searchString = "(7,32)";
    Pattern compile1 = Pattern.compile("\\(\\d+,");
    Pattern compile2 = Pattern.compile(",\\d+\\)");
    Matcher matcher1 = compile1.matcher(searchString);
    Matcher matcher2 = compile2.matcher(searchString);
    while (matcher1.find() && matcher2.find()) {
        String group1 = matcher1.group();
        String group2 = matcher2.group();
        System.out.println("value 1: " + group1.substring(1, group1.length() - 1 ) + " value 2: " + group2.substring(1, group2.length() - 1 ));
    }
}

Not that I think regex is the best to use here. If you know the input will be in the form of: (number, number), I would first get rid of brackets:

stringWithoutBrackets = searchString.substring(1, searchString.length()-1) 

and than tokenize it with split

String[] coordiantes = stringWithoutBrackets.split(",");

Looked through Regex API and you can also do something like this:

public static void main(String[] args) {
    String searchString = "(7,32)";
    Pattern compile1 = Pattern.compile("(?<=\\()\\d+(?=,)");
    Pattern compile2 = Pattern.compile("(?<=,)\\d+(?=\\))");
    Matcher matcher1 = compile1.matcher(searchString);
    Matcher matcher2 = compile2.matcher(searchString);
    while (matcher1.find() && matcher2.find()) {
        String group1 = matcher1.group();
        String group2 = matcher2.group();
        System.out.println("value 1: " + group1 + " value 2: " + group2);
    }
}

The main change is that I used (?<==\)), (?=,), (?<=,), (?=\)), to search for brackets and commas but not caputre them. But I really think its an overkill for this task.