Java:
Пошук та заміна тексту

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class TextSearchReplace {
    public static void main(String[] args) {
        String text = "Hello, this is a test. This test is simple.";
        String searchText = "test";
        String replaceText = "example";

        // Простий пошук і заміна
        String replacedText = text.replaceAll(searchText, replaceText);
        System.out.println(replacedText);  // Hello, this is an example. This example is simple.

        // Використання регулярних виразів
        Pattern pattern = Pattern.compile("(test)(\\s+)(is)", Pattern.CASE_INSENSITIVE);
        Matcher matcher = pattern.matcher(text);

        StringBuffer resultText = new StringBuffer();
        while (matcher.find()) {
            matcher.appendReplacement(resultText, "demo$2was");
        }
        matcher.appendTail(resultText);

        System.out.println(resultText.toString());  // Hello, this is a demo was simple. This demo was simple.
    }
}