Trim from a space or tab onward or backwards in Java

Question

I know how to trim things in Java but how does one trim from a space or tab to the left or to the right? I have a program that searches for some 4 character prefixes let’s say this prefix is XYBC then it has X amount of characters to it like XYBC4975723434 but the line that my code takes looks like this:

Viuhaskfdksjfkds XYBC4975723434 fkdsjkfjaksjfklsdakldjsen

But then I would like it to trim it to this: XYBC4975723434 Thanks

Answer 1

That is not a trim, but a regular expression find, using the following regex:

\bXYBC.*?\b

That expression used word boundaries, which may not be what you want.

For whitespace, use:

(?<=^|\s)XYBC\S*

Test

public static void main(String[] args) {
    test("Viuhaskfdksjfkds  XYBC4975723434 fkdsjkfjaksjfklsdakldjsen");
    test("XYBC4975723434");
    test("Viuhaskfdksjfkds  xXYBC4975723434 fkdsjkfjaksjfklsdakldjsen");
    test("abc XYBC49-75(723)4$34 xyz");
}
private static void test(String text) {
    Matcher m = Pattern.compile("\\bXYBC.*?\\b").matcher(text);
    if (m.find()) {
        System.out.println(m.group());
    } else {
        System.out.println("Not found: " + text);
    }
}

Output (word boundary)

XYBC4975723434
XYBC4975723434
Not found: Viuhaskfdksjfkds  xXYBC4975723434 fkdsjkfjaksjfklsdakldjsen
XYBC49

Output (whitespace)

XYBC4975723434
XYBC4975723434
Not found: Viuhaskfdksjfkds  xXYBC4975723434 fkdsjkfjaksjfklsdakldjsen
XYBC49-75(723)4$34