I THINK Latin characters are what I mean in my question, but I'm not entirely sure what the correct classification is. I'm trying to use a regex Pattern to test if a string contains non Latin characters. I'm expecting the following results
"abcDE 123"; // Yes, this should match
"!@#$%^&*"; // Yes, this should match
"aaàààäää"; // Yes, this should match
"ベビードラ"; // No, this shouldn't match
"😀😃😄😆"; // No, this shouldn't match
My understanding is that the built-in {IsLatin}
preset simply detects if any of the characters are Latin. I want to detect if any characters are not Latin.
Pattern LatinPattern = Pattern.compile("\\p{IsLatin}");
Matcher matcher = LatinPattern.matcher(str);
if (!matcher.find()) {
System.out.println("is NON latin");
return;
}
System.out.println("is latin");
TL;DR: Use regex ^[\p{Print}\p{IsLatin}]*$
You want a regex that matches if the string consists of:
Easiest way is to combine \p{IsLatin}
with \p{Print}
, where Pattern
defines \p{Print}
as:
\p{Print}
- A printable character: [\p{Graph}\x20]
\p{Graph}
- A visible character: [\p{Alnum}\p{Punct}]
\p{Alnum}
- An alphanumeric character: [\p{Alpha}\p{Digit}]
\p{Alpha}
- An alphabetic character: [\p{Lower}\p{Upper}]
\p{Lower}
- A lower-case alphabetic character: [a-z]
\p{Upper}
- An upper-case alphabetic character: [A-Z]
\p{Digit}
- A decimal digit: [0-9]
\p{Punct}
- Punctuation: One of !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~
\x20
- A space:
Which makes \p{Print}
the same as [\p{ASCII}&&\P{Cntrl}]
, i.e. ASCII characters that are not control characters.
The \p{Alpha}
part overlaps with \p{IsLatin}
, but that's fine, since the character class eliminates duplicates.
So, regex is: ^[\p{Print}\p{IsLatin}]*$
Test
Pattern latinPattern = Pattern.compile("^[\\p{Print}\\p{IsLatin}]*$");
String[] inputs = { "abcDE 123", "!@#$%^&*", "aaàààäää", "ベビードラ", "😀😃😄😆" };
for (String input : inputs) {
System.out.print("\"" + input + "\": ");
Matcher matcher = latinPattern.matcher(input);
if (! matcher.find()) {
System.out.println("is NON latin");
} else {
System.out.println("is latin");
}
}
Output
"abcDE 123": is latin
"!@#$%^&*": is latin
"aaàààäää": is latin
"ベビードラ": is NON latin
"😀😃😄😆": is NON latin