How to find the exact word using a regex in Java?

Question

Consider the following code snippet:

String input = \"Print this\";
System.out.println(input.matches(\"\\\\bthis\\\\b\"));

Output

Answer 1

When you use the matches() method, it is trying to match the entire input. In your example, the input "Print this" doesn't match the pattern because the word "Print" isn't matched.

So you need to add something to the regex to match the initial part of the string, e.g.

.*\\bthis\\b

And if you want to allow extra text at the end of the line too:

.*\\bthis\\b.*

Alternatively, use a Matcher object and use Matcher.find() to find matches within the input string:

    Pattern p = Pattern.compile("\\bthis\\b");
    Matcher m = p.matcher("Print this");
    m.find();
    System.out.println(m.group());

Output:

this

If you want to find multiple matches in a line, you can call find() and group() repeatedly to extract them all.