Unicode 属性转义

The classes \w, \d, \s in ASCII are not enough for Italian, French, Greek or emoji text. Modern JavaScript (with the u flag -- Unicode) offers property escapes \p{...}: semantic classes based on the Unicode properties of characters.

Pattern: \p{L}+        (with flag u)
Sample:  Ciao caffe' \u00fcber \u4e16\u754c
         ^^^^ ^^^^^^^ ^^^^ ^^^^

\p{L} = "any Letter (Unicode)": includes accented letters, Chinese ideograms, Cyrillic, Greek\u2026 everything. The most common ones:

• \p{L} -- letter (of any alphabet).
• \p{N} -- number (Arabic digits, Roman, Indian\u2026).
• \p{P} -- punctuation.
• \p{S} -- symbol (mathematical, currency, emoji\u2026).
• \p{Z} -- space/separator.
• \p{Script=Latin} -- specifically the Latin alphabet.
• \p{Script=Greek} -- the Greek alphabet. And so on.

And the negated versions \P{L}, \P{N}, \u2026

Difference with \w and \d

\\w matches [A-Za-z0-9_]              -- ASCII only, no "caffe'"
\\p{L}\\p{N}_  with flag u            -- includes accented characters

For a robust parser of Italian text, prefer \p{L} over \w: citta', perche', andro' correctly match as words.

Unicode properties and browser compatibility

Unicode properties like \\p{L} (Letters) or \\p{Script=Latin} extend classes to international alphabets. In JavaScript, they strictly require the u (or v) flag, otherwise the engine throws a syntax error.

Try it

Review exercise

Additional challenge