Java — RegEx

Pattern and Matcher

import java.util.regex.*;

Pattern p = Pattern.compile("\\d+");
Matcher m = p.matcher("abc123def456");

while (m.find()) {
    System.out.println(m.group());
}

Common patterns

\\d    // Digit
\\w    // Word character
\\s    // Whitespace
.      // Any character
*      // Zero or more
+      // One or more
?      // Zero or one
{n}    // Exactly n

String methods

"hello123".matches(".*\\d.*");  // true
"hello".replaceAll("l", "L");   // "heLLo"

Mini Practice

1. Create pattern
2. Find matches
3. Replace with regex
4. Practice patterns

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