\d less efficient than [0-9]

Question

I made a comment yesterday on an answer where someone had used [0123456789] in a regex rather than [0-9] or \d. I said it was probably more efficient to use a range or digit specifier than a character set.

I decided to test that out today and found out to my surprise that (in the c# regex engine at least) \d appears to be less efficient than either of the other two which don't seem to differ much. Here is my test output over 10000 random strings of 1000 random characters with 5077 actually containing a digit:

Regex \d           took 00:00:00.2141226 result: 5077/10000
Regex [0-9]        took 00:00:00.1357972 result: 5077/10000  63.42 % of first
Regex [0123456789] took 00:00:00.1388997 result: 5077/10000  64.87 % of first

It's a surprise to me for two reasons, that I would be interested if anyone can shed some light on:

1. I would have thought the range would be implemented much more efficiently than the set.
2. I can't understand why \d is worse than [0-9]. Is there more to \d than simply shorthand for [0-9]?

Here is the test code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Text.RegularExpressions;

namespace SO_RegexPerformance
{
    class Program
    {
        static void Main(string[] args)
        {
            var rand = new Random(1234);
            var strings = new List<string>();
            //10K random strings
            for (var i = 0; i < 10000; i++)
            {
                //generate random string
                var sb = new StringBuilder();
                for (var c = 0; c < 1000; c++)
                {
                    //add a-z randomly
                    sb.Append((char)('a' + rand.Next(26)));
                }
                //in roughly 50% of them, put a digit
                if (rand.Next(2) == 0)
                {
                    //replace 1 char with a digit 0-9
                    sb[rand.Next(sb.Length)] = (char)('0' + rand.Next(10));
                }
                strings.Add(sb.ToString());
            }

            var baseTime = testPerfomance(strings, @"\d");
            Console.WriteLine();
            var testTime = testPerfomance(strings, "[0-9]");
            Console.WriteLine("  {0:P2} of first", testTime.TotalMilliseconds / baseTime.TotalMilliseconds);
            testTime = testPerfomance(strings, "[0123456789]");
            Console.WriteLine("  {0:P2} of first", testTime.TotalMilliseconds / baseTime.TotalMilliseconds);
        }

        private static TimeSpan testPerfomance(List<string> strings, string regex)
        {
            var sw = new Stopwatch();

            int successes = 0;

            var rex = new Regex(regex);

            sw.Start();
            foreach (var str in strings)
            {
                if (rex.Match(str).Success)
                {
                    successes++;
                }
            }
            sw.Stop();

            Console.Write("Regex {0,-12} took {1} result: {2}/{3}", regex, sw.Elapsed, successes, strings.Count);

            return sw.Elapsed;
        }
    }
}

Answer 1

\d checks all Unicode digits, while [0-9] is limited to these 10 characters. For example, Persian digits, ۱۲۳۴۵۶۷۸۹, are an example of Unicode digits which are matched with \d, but not [0-9].

You can generate a list of all such characters using the following code:

var sb = new StringBuilder();
for(UInt16 i = 0; i < UInt16.MaxValue; i++)
{
    string str = Convert.ToChar(i).ToString();
    if (Regex.IsMatch(str, @"\d"))
        sb.Append(str);
}
Console.WriteLine(sb.ToString());

Which generates:

0123456789٠١٢٣٤٥٦٧٨٩۰۱۲۳۴۵۶۷۸۹߀߁߂߃߄߅߆߇߈߉०१२३४५६७८९০১২৩৪৫৬৭৮৯੦੧੨੩੪੫੬੭੮੯૦૧૨૩૪૫૬૭૮૯୦୧୨୩୪୫୬୭୮୯௦௧௨௩௪௫௬௭௮௯౦౧౨౩౪౫౬౭౮౯೦೧೨೩೪೫೬೭೮೯൦൧൨൩൪൫൬൭൮൯๐๑๒๓๔๕๖๗๘๙໐໑໒໓໔໕໖໗໘໙༠༡༢༣༤༥༦༧༨༩၀၁၂၃၄၅၆၇၈၉႐႑႒႓႔႕႖႗႘႙០១២៣៤៥៦៧៨៩᠐᠑᠒᠓᠔᠕᠖᠗᠘᠙᥆᥇᥈᥉᥊᥋᥌᥍᥎᥏᧐᧑᧒᧓᧔᧕᧖᧗᧘᧙᭐᭑᭒᭓᭔᭕᭖᭗᭘᭙᮰᮱᮲᮳᮴᮵᮶᮷᮸᮹᱀᱁᱂᱃᱄᱅᱆᱇᱈᱉᱐᱑᱒᱓᱔᱕᱖᱗᱘᱙꘠꘡꘢꘣꘤꘥꘦꘧꘨꘩꣐꣑꣒꣓꣔꣕꣖꣗꣘꣙꤀꤁꤂꤃꤄꤅꤆꤇꤈꤉꩐꩑꩒꩓꩔꩕꩖꩗꩘꩙０１２３４５６７８９

Answer 2

Credit to ByteBlast for noticing this in the docs. Just changing the regex constructor:

var rex = new Regex(regex, RegexOptions.ECMAScript);

Gives new timings:

Regex \d           took 00:00:00.1355787 result: 5077/10000
Regex [0-9]        took 00:00:00.1360403 result: 5077/10000  100.34 % of first
Regex [0123456789] took 00:00:00.1362112 result: 5077/10000  100.47 % of first

Answer 3

From Does “\d” in regex mean a digit?:

[0-9] isn't equivalent to \d. [0-9] matches only 0123456789 characters, while \d matches [0-9] and other digit characters, for example Eastern Arabic numerals ٠١٢٣٤٥٦٧٨٩

Answer 4

An addition to top answer from Sina Iravianian, here is a .NET 4.5 version (since only that version supports UTF16 output, c.f. the first three lines) of his code, using the full range of Unicode code points. Due to the lack of proper support for higher Unicode planes, many people are not aware of always checking for and including the upper Unicode planes. Nevertheless they sometimes do contain some important characters.

Update

Since \d does not support non-BMP characters in regex (thanks xanatos), here a version that uses the Unicode character database

Update 2

Thanks to damilola-adegunwa, I have added the missing reference to the UCD (via NuGet package UnicodeInformation). Also udpated to the latest .NET core version and UTF-8 output.

// reference https://www.nuget.org/packages/UnicodeInformation/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Globalization;
using System.Unicode;
                    
public class Program
{
    public static void Main()
    {
        var unicodeEncoding = new UTF8Encoding(false);
        Console.OutputEncoding = unicodeEncoding;

        var numberCategories = new HashSet<UnicodeCategory>(new []{
            UnicodeCategory.DecimalDigitNumber,
            UnicodeCategory.LetterNumber,
            UnicodeCategory.OtherNumber
        });
        var numberLikeChars =
            from codePoint in Enumerable.Range(0, 0x10ffff)
            where codePoint > UInt16.MaxValue 
                || (!char.IsLowSurrogate((char) codePoint) && !char.IsHighSurrogate((char) codePoint))
            let charInfo = UnicodeInfo.GetCharInfo(codePoint)
            where numberCategories.Contains(charInfo.Category)
            let codePointString = char.ConvertFromUtf32(codePoint)
            select (codePoint, charInfo, codePointString);

        foreach (var (codePoint, charInfo, codePointString) in numberLikeChars)
        {
            Console.Write("U+{0} ", codePoint.ToString("X6"));
            Console.Write(" {0,-4}", codePointString);
            Console.Write(" {0,-40}", charInfo.Name ?? charInfo.OldName);
            Console.Write(" {0,-6}", CharUnicodeInfo.GetNumericValue(codePointString, 0));
            Console.Write(" {0,-6}", CharUnicodeInfo.GetDigitValue(codePointString, 0));
            Console.Write(" {0,-6}", CharUnicodeInfo.GetDecimalDigitValue(codePointString, 0));
            Console.WriteLine(" {0}", charInfo.Category);
        }
    }
}

Yielding the following output:

U+000030  0    DIGIT ZERO                               0      0      0      DecimalDigitNumber
U+000031  1    DIGIT ONE                                1      1      1      DecimalDigitNumber
U+000032  2    DIGIT TWO                                2      2      2      DecimalDigitNumber
U+000033  3    DIGIT THREE                              3      3      3      DecimalDigitNumber
U+000034  4    DIGIT FOUR                               4      4      4      DecimalDigitNumber
U+000035  5    DIGIT FIVE                               5      5      5      DecimalDigitNumber
U+000036  6    DIGIT SIX                                6      6      6      DecimalDigitNumber
U+000037  7    DIGIT SEVEN                              7      7      7      DecimalDigitNumber
U+000038  8    DIGIT EIGHT                              8      8      8      DecimalDigitNumber
U+000039  9    DIGIT NINE                               9      9      9      DecimalDigitNumber
U+0000B2  ²    SUPERSCRIPT TWO                          2      2      -1     OtherNumber
U+0000B3  ³    SUPERSCRIPT THREE                        3      3      -1     OtherNumber
U+0000B9  ¹    SUPERSCRIPT ONE                          1      1      -1     OtherNumber
U+0000BC  ¼    VULGAR FRACTION ONE QUARTER              0.25   -1     -1     OtherNumber
U+0000BD  ½    VULGAR FRACTION ONE HALF                 0.5    -1     -1     OtherNumber
U+0000BE  ¾    VULGAR FRACTION THREE QUARTERS           0.75   -1     -1     OtherNumber
U+000660  ٠    ARABIC-INDIC DIGIT ZERO                  0      0      0      DecimalDigitNumber
U+000661  ١    ARABIC-INDIC DIGIT ONE                   1      1      1      DecimalDigitNumber
U+000662  ٢    ARABIC-INDIC DIGIT TWO                   2      2      2      DecimalDigitNumber
U+000663  ٣    ARABIC-INDIC DIGIT THREE                 3      3      3      DecimalDigitNumber
U+000664  ٤    ARABIC-INDIC DIGIT FOUR                  4      4      4      DecimalDigitNumber
U+000665  ٥    ARABIC-INDIC DIGIT FIVE                  5      5      5      DecimalDigitNumber
U+000666  ٦    ARABIC-INDIC DIGIT SIX                   6      6      6      DecimalDigitNumber
U+000667  ٧    ARABIC-INDIC DIGIT SEVEN                 7      7      7      DecimalDigitNumber
U+000668  ٨    ARABIC-INDIC DIGIT EIGHT                 8      8      8      DecimalDigitNumber
U+000669  ٩    ARABIC-INDIC DIGIT NINE                  9      9      9      DecimalDigitNumber
U+0006F0  ۰    EXTENDED ARABIC-INDIC DIGIT ZERO         0      0      0      DecimalDigitNumber
U+0006F1  ۱    EXTENDED ARABIC-INDIC DIGIT ONE          1      1      1      DecimalDigitNumber
U+0006F2  ۲    EXTENDED ARABIC-INDIC DIGIT TWO          2      2      2      DecimalDigitNumber
U+0006F3  ۳    EXTENDED ARABIC-INDIC DIGIT THREE        3      3      3      DecimalDigitNumber
U+0006F4  ۴    EXTENDED ARABIC-INDIC DIGIT FOUR         4      4      4      DecimalDigitNumber
U+0006F5  ۵    EXTENDED ARABIC-INDIC DIGIT FIVE         5      5      5      DecimalDigitNumber
U+0006F6  ۶    EXTENDED ARABIC-INDIC DIGIT SIX          6      6      6      DecimalDigitNumber
U+0006F7  ۷    EXTENDED ARABIC-INDIC DIGIT SEVEN        7      7      7      DecimalDigitNumber
U+0006F8  ۸    EXTENDED ARABIC-INDIC DIGIT EIGHT        8      8      8      DecimalDigitNumber
U+0006F9  ۹    EXTENDED ARABIC-INDIC DIGIT NINE         9      9      9      DecimalDigitNumber
U+0007C0  ߀    NKO DIGIT ZERO                           0      0      0      DecimalDigitNumber
U+0007C1  ߁    NKO DIGIT ONE                            1      1      1      DecimalDigitNumber
U+0007C2  ߂    NKO DIGIT TWO                            2      2      2      DecimalDigitNumber
U+0007C3  ߃    NKO DIGIT THREE                          3      3      3      DecimalDigitNumber
U+0007C4  ߄    NKO DIGIT FOUR                           4      4      4      DecimalDigitNumber
U+0007C5  ߅    NKO DIGIT FIVE                           5      5      5      DecimalDigitNumber
U+0007C6  ߆    NKO DIGIT SIX                            6      6      6      DecimalDigitNumber
U+0007C7  ߇    NKO DIGIT SEVEN                          7      7      7      DecimalDigitNumber
U+0007C8  ߈    NKO DIGIT EIGHT                          8      8      8      DecimalDigitNumber
U+0007C9  ߉    NKO DIGIT NINE                           9      9      9      DecimalDigitNumber
U+000966  ०    DEVANAGARI DIGIT ZERO                    0      0      0      DecimalDigitNumber
U+000967  १    DEVANAGARI DIGIT ONE                     1      1      1      DecimalDigitNumber
U+000968  २    DEVANAGARI DIGIT TWO                     2      2      2      DecimalDigitNumber
U+000969  ३    DEVANAGARI DIGIT THREE                   3      3      3      DecimalDigitNumber
U+00096A  ४    DEVANAGARI DIGIT FOUR                    4      4      4      DecimalDigitNumber
U+00096B  ५    DEVANAGARI DIGIT FIVE                    5      5      5      DecimalDigitNumber
U+00096C  ६    DEVANAGARI DIGIT SIX                     6      6      6      DecimalDigitNumber
U+00096D  ७    DEVANAGARI DIGIT SEVEN                   7      7      7      DecimalDigitNumber
U+00096E  ८    DEVANAGARI DIGIT EIGHT                   8      8      8      DecimalDigitNumber
U+00096F  ९    DEVANAGARI DIGIT NINE                    9      9      9      DecimalDigitNumber
U+0009E6  ০    BENGALI DIGIT ZERO                       0      0      0      DecimalDigitNumber
U+0009E7  ১    BENGALI DIGIT ONE                        1      1      1      DecimalDigitNumber
U+0009E8  ২    BENGALI DIGIT TWO                        2      2      2      DecimalDigitNumber
U+0009E9  ৩    BENGALI DIGIT THREE                      3      3      3      DecimalDigitNumber
U+0009EA  ৪    BENGALI DIGIT FOUR                       4      4      4      DecimalDigitNumber
U+0009EB  ৫    BENGALI DIGIT FIVE                       5      5      5      DecimalDigitNumber
U+0009EC  ৬    BENGALI DIGIT SIX                        6      6      6      DecimalDigitNumber
U+0009ED  ৭    BENGALI DIGIT SEVEN                      7      7      7      DecimalDigitNumber
U+0009EE  ৮    BENGALI DIGIT EIGHT                      8      8      8      DecimalDigitNumber
U+0009EF  ৯    BENGALI DIGIT NINE                       9      9      9      DecimalDigitNumber
U+0009F4  ৴    BENGALI CURRENCY NUMERATOR ONE           0.0625 -1     -1     OtherNumber
U+0009F5  ৵    BENGALI CURRENCY NUMERATOR TWO           0.125  -1     -1     OtherNumber
U+0009F6  ৶    BENGALI CURRENCY NUMERATOR THREE         0.1875 -1     -1     OtherNumber
U+0009F7  ৷    BENGALI CURRENCY NUMERATOR FOUR          0.25   -1     -1     OtherNumber
U+0009F8  ৸    BENGALI CURRENCY NUMERATOR ONE LESS THAN THE DENOMINATOR 0.75   -1     -1     OtherNumber
U+0009F9  ৹    BENGALI CURRENCY DENOMINATOR SIXTEEN     16     -1     -1     OtherNumber
U+000A66  ੦    GURMUKHI DIGIT ZERO                      0      0      0      DecimalDigitNumber
U+000A67  ੧    GURMUKHI DIGIT ONE                       1      1      1      DecimalDigitNumber
U+000A68  ੨    GURMUKHI DIGIT TWO                       2      2      2      DecimalDigitNumber
U+000A69  ੩    GURMUKHI DIGIT THREE                     3      3      3      DecimalDigitNumber
U+000A6A  ੪    GURMUKHI DIGIT FOUR                      4      4      4      DecimalDigitNumber
U+000A6B  ੫    GURMUKHI DIGIT FIVE                      5      5      5      DecimalDigitNumber
U+000A6C  ੬    GURMUKHI DIGIT SIX                       6      6      6      DecimalDigitNumber
U+000A6D  ੭    GURMUKHI DIGIT SEVEN                     7      7      7      DecimalDigitNumber
U+000A6E  ੮    GURMUKHI DIGIT EIGHT                     8      8      8      DecimalDigitNumber
U+000A6F  ੯    GURMUKHI DIGIT NINE                      9      9      9      DecimalDigitNumber
U+000AE6  ૦    GUJARATI DIGIT ZERO                      0      0      0      DecimalDigitNumber
U+000AE7  ૧    GUJARATI DIGIT ONE                       1      1      1      DecimalDigitNumber
U+000AE8  ૨    GUJARATI DIGIT TWO                       2      2      2      DecimalDigitNumber
U+000AE9  ૩    GUJARATI DIGIT THREE                     3      3      3      DecimalDigitNumber
U+000AEA  ૪    GUJARATI DIGIT FOUR                      4      4      4      DecimalDigitNumber
U+000AEB  ૫    GUJARATI DIGIT FIVE                      5      5      5      DecimalDigitNumber
U+000AEC  ૬    GUJARATI DIGIT SIX                       6      6      6      DecimalDigitNumber
U+000AED  ૭    GUJARATI DIGIT SEVEN                     7      7      7      DecimalDigitNumber
U+000AEE  ૮    GUJARATI DIGIT EIGHT                     8      8      8      DecimalDigitNumber
U+000AEF  ૯    GUJARATI DIGIT NINE                      9      9      9      DecimalDigitNumber
U+000B66  ୦    ORIYA DIGIT ZERO                         0      0      0      DecimalDigitNumber
U+000B67  ୧    ORIYA DIGIT ONE                          1      1      1      DecimalDigitNumber
U+000B68  ୨    ORIYA DIGIT TWO                          2      2      2      DecimalDigitNumber
U+000B69  ୩    ORIYA DIGIT THREE                        3      3      3      DecimalDigitNumber
U+000B6A  ୪    ORIYA DIGIT FOUR                         4      4      4      DecimalDigitNumber
U+000B6B  ୫    ORIYA DIGIT FIVE                         5      5      5      DecimalDigitNumber
U+000B6C  ୬    ORIYA DIGIT SIX                          6      6      6      DecimalDigitNumber
U+000B6D  ୭    ORIYA DIGIT SEVEN                        7      7      7      DecimalDigitNumber
U+000B6E  ୮    ORIYA DIGIT EIGHT                        8      8      8      DecimalDigitNumber
U+000B6F  ୯    ORIYA DIGIT NINE                         9      9      9      DecimalDigitNumber
U+000B72  ୲    ORIYA FRACTION ONE QUARTER               0.25   -1     -1     OtherNumber
U+000B73  ୳    ORIYA FRACTION ONE HALF                  0.5    -1     -1     OtherNumber
U+000B74  ୴    ORIYA FRACTION THREE QUARTERS            0.75   -1     -1     OtherNumber
U+000B75  ୵    ORIYA FRACTION ONE SIXTEENTH             0.0625 -1     -1     OtherNumber
U+000B76  ୶    ORIYA FRACTION ONE EIGHTH                0.125  -1     -1     OtherNumber
U+000B77  ୷    ORIYA FRACTION THREE SIXTEENTHS          0.1875 -1     -1     OtherNumber
U+000BE6  ௦    TAMIL DIGIT ZERO                         0      0      0      DecimalDigitNumber
U+000BE7  ௧    TAMIL DIGIT ONE                          1      1      1      DecimalDigitNumber
U+000BE8  ௨    TAMIL DIGIT TWO                          2      2      2      DecimalDigitNumber
U+000BE9  ௩    TAMIL DIGIT THREE                        3      3      3      DecimalDigitNumber
U+000BEA  ௪    TAMIL DIGIT FOUR                         4      4      4      DecimalDigitNumber
U+000BEB  ௫    TAMIL DIGIT FIVE                         5      5      5      DecimalDigitNumber
U+000BEC  ௬    TAMIL DIGIT SIX                          6      6      6      DecimalDigitNumber
U+000BED  ௭    TAMIL DIGIT SEVEN                        7      7      7      DecimalDigitNumber
U+000BEE  ௮    TAMIL DIGIT EIGHT                        8      8      8      DecimalDigitNumber
U+000BEF  ௯    TAMIL DIGIT NINE                         9      9      9      DecimalDigitNumber
U+000BF0  ௰    TAMIL NUMBER TEN                         10     -1     -1     OtherNumber
U+000BF1  ௱    TAMIL NUMBER ONE HUNDRED                 100    -1     -1     OtherNumber
U+000BF2  ௲    TAMIL NUMBER ONE THOUSAND                1000   -1     -1     OtherNumber
U+000C66  ౦    TELUGU DIGIT ZERO                        0      0      0      DecimalDigitNumber
U+000C67  ౧    TELUGU DIGIT ONE                         1      1      1      DecimalDigitNumber
U+000C68  ౨    TELUGU DIGIT TWO                         2      2      2      DecimalDigitNumber
U+000C69  ౩    TELUGU DIGIT THREE                       3      3      3      DecimalDigitNumber
U+000C6A  ౪    TELUGU DIGIT FOUR                        4      4      4      DecimalDigitNumber
U+000C6B  ౫    TELUGU DIGIT FIVE                        5      5      5      DecimalDigitNumber
U+000C6C  ౬    TELUGU DIGIT SIX                         6      6      6      DecimalDigitNumber
U+000C6D  ౭    TELUGU DIGIT SEVEN                       7      7      7      DecimalDigitNumber
U+000C6E  ౮    TELUGU DIGIT EIGHT                       8      8      8      DecimalDigitNumber
U+000C6F  ౯    TELUGU DIGIT NINE                        9      9      9      DecimalDigitNumber
U+000C78  ౸    TELUGU FRACTION DIGIT ZERO FOR ODD POWERS OF FOUR 0      -1     -1     OtherNumber
U+000C79  ౹    TELUGU FRACTION DIGIT ONE FOR ODD POWERS OF FOUR 1      -1     -1     OtherNumber
U+000C7A  ౺    TELUGU FRACTION DIGIT TWO FOR ODD POWERS OF FOUR 2      -1     -1     OtherNumber
U+000C7B  ౻    TELUGU FRACTION DIGIT THREE FOR ODD POWERS OF FOUR 3      -1     -1     OtherNumber
U+000C7C  ౼    TELUGU FRACTION DIGIT ONE FOR EVEN POWERS OF FOUR 1      -1     -1     OtherNumber
U+000C7D  ౽    TELUGU FRACTION DIGIT TWO FOR EVEN POWERS OF FOUR 2      -1     -1     OtherNumber
U+000C7E  ౾    TELUGU FRACTION DIGIT THREE FOR EVEN POWERS OF FOUR 3      -1     -1     OtherNumber
U+000CE6  ೦    KANNADA DIGIT ZERO                       0      0      0      DecimalDigitNumber
U+000CE7  ೧    KANNADA DIGIT ONE                        1      1      1      DecimalDigitNumber
U+000CE8  ೨    KANNADA DIGIT TWO                        2      2      2      DecimalDigitNumber
U+000CE9  ೩    KANNADA DIGIT THREE                      3      3      3      DecimalDigitNumber
U+000CEA  ೪    KANNADA DIGIT FOUR                       4      4      4      DecimalDigitNumber
U+000CEB  ೫    KANNADA DIGIT FIVE                       5      5      5      DecimalDigitNumber
U+000CEC  ೬    KANNADA DIGIT SIX                        6      6      6      DecimalDigitNumber
U+000CED  ೭    KANNADA DIGIT SEVEN                      7      7      7      DecimalDigitNumber
U+000CEE  ೮    KANNADA DIGIT EIGHT                      8      8      8      DecimalDigitNumber
U+000CEF  ೯    KANNADA DIGIT NINE                       9      9      9      DecimalDigitNumber
U+000D58  ൘    MALAYALAM FRACTION ONE ONE-HUNDRED-AND-SIXTIETH 0.00625 -1     -1     OtherNumber
U+000D59  ൙    MALAYALAM FRACTION ONE FORTIETH          0.025  -1     -1     OtherNumber
U+000D5A  ൚    MALAYALAM FRACTION THREE EIGHTIETHS      0.0375 -1     -1     OtherNumber
U+000D5B  ൛    MALAYALAM FRACTION ONE TWENTIETH         0.05   -1     -1     OtherNumber
U+000D5C  ൜    MALAYALAM FRACTION ONE TENTH             0.1    -1     -1     OtherNumber
U+000D5D  ൝    MALAYALAM FRACTION THREE TWENTIETHS      0.15   -1     -1     OtherNumber
U+000D5E  ൞    MALAYALAM FRACTION ONE FIFTH             0.2    -1     -1     OtherNumber
U+000D66  ൦    MALAYALAM DIGIT ZERO                     0      0      0      DecimalDigitNumber
U+000D67  ൧    MALAYALAM DIGIT ONE                      1      1      1      DecimalDigitNumber
U+000D68  ൨    MALAYALAM DIGIT TWO                      2      2      2      DecimalDigitNumber
U+000D69  ൩    MALAYALAM DIGIT THREE                    3      3      3      DecimalDigitNumber
U+000D6A  ൪    MALAYALAM DIGIT FOUR                     4      4      4      DecimalDigitNumber
U+000D6B  ൫    MALAYALAM DIGIT FIVE                     5      5      5      DecimalDigitNumber
U+000D6C  ൬    MALAYALAM DIGIT SIX                      6      6      6      DecimalDigitNumber
U+000D6D  ൭    MALAYALAM DIGIT SEVEN                    7      7      7      DecimalDigitNumber
U+000D6E  ൮    MALAYALAM DIGIT EIGHT                    8      8      8      DecimalDigitNumber
U+000D6F  ൯    MALAYALAM DIGIT NINE                     9      9      9      DecimalDigitNumber
U+000D70  ൰    MALAYALAM NUMBER TEN                     10     -1     -1     OtherNumber
U+000D71  ൱    MALAYALAM NUMBER ONE HUNDRED             100    -1     -1     OtherNumber
U+000D72  ൲    MALAYALAM NUMBER ONE THOUSAND            1000   -1     -1     OtherNumber
U+000D73  ൳    MALAYALAM FRACTION ONE QUARTER           0.25   -1     -1     OtherNumber
U+000D74  ൴    MALAYALAM FRACTION ONE HALF              0.5    -1     -1     OtherNumber
U+000D75  ൵    MALAYALAM FRACTION THREE QUARTERS        0.75   -1     -1     OtherNumber
U+000D76  ൶    MALAYALAM FRACTION ONE SIXTEENTH         0.0625 -1     -1     OtherNumber
U+000D77  ൷    MALAYALAM FRACTION ONE EIGHTH            0.125  -1     -1     OtherNumber
U+000D78  ൸    MALAYALAM FRACTION THREE SIXTEENTHS      0.1875 -1     -1     OtherNumber
U+000DE6  ෦    SINHALA LITH DIGIT ZERO                  0      0      0      DecimalDigitNumber
U+000DE7  ෧    SINHALA LITH DIGIT ONE                   1      1      1      DecimalDigitNumber
U+000DE8  ෨    SINHALA LITH DIGIT TWO                   2      2      2      DecimalDigitNumber
U+000DE9  ෩    SINHALA LITH DIGIT THREE                 3      3      3      DecimalDigitNumber
U+000DEA  ෪    SINHALA LITH DIGIT FOUR                  4      4      4      DecimalDigitNumber
U+000DEB  ෫    SINHALA LITH DIGIT FIVE                  5      5      5      DecimalDigitNumber
U+000DEC  ෬    SINHALA LITH DIGIT SIX                   6      6      6      DecimalDigitNumber
U+000DED  ෭    SINHALA LITH DIGIT SEVEN                 7      7      7      DecimalDigitNumber
U+000DEE  ෮    SINHALA LITH DIGIT EIGHT                 8      8      8      DecimalDigitNumber
U+000DEF  ෯    SINHALA LITH DIGIT NINE                  9      9      9      DecimalDigitNumber
U+000E50  ๐    THAI DIGIT ZERO                          0      0      0      DecimalDigitNumber
U+000E51  ๑    THAI DIGIT ONE                           1      1      1      DecimalDigitNumber
U+000E52  ๒    THAI DIGIT TWO                           2      2      2      DecimalDigitNumber
U+000E53  ๓    THAI DIGIT THREE                         3      3      3      DecimalDigitNumber
U+000E54  ๔    THAI DIGIT FOUR                          4      4      4      DecimalDigitNumber
U+000E55  ๕    THAI DIGIT FIVE                          5      5      5      DecimalDigitNumber
U+000E56  ๖    THAI DIGIT SIX                           6      6      6      DecimalDigitNumber
U+000E57  ๗    THAI DIGIT SEVEN                         7      7      7      DecimalDigitNumber
U+000E58  ๘    THAI DIGIT EIGHT                         8      8      8      DecimalDigitNumber
U+000E59  ๙    THAI DIGIT NINE                          9      9      9      DecimalDigitNumber
U+000ED0  ໐    LAO DIGIT ZERO                           0      0      0      DecimalDigitNumber
U+000ED1  ໑    LAO DIGIT ONE                            1      1      1      DecimalDigitNumber
U+000ED2  ໒    LAO DIGIT TWO                            2      2      2      DecimalDigitNumber
U+000ED3  ໓    LAO DIGIT THREE                          3      3      3      DecimalDigitNumber
U+000ED4  ໔    LAO DIGIT FOUR                           4      4      4      DecimalDigitNumber
U+000ED5  ໕    LAO DIGIT FIVE                           5      5      5      DecimalDigitNumber
U+000ED6  ໖    LAO DIGIT SIX                            6      6      6      DecimalDigitNumber
U+000ED7  ໗    LAO DIGIT SEVEN                          7      7      7      DecimalDigitNumber
U+000ED8  ໘    LAO DIGIT EIGHT                          8      8      8      DecimalDigitNumber
U+000ED9  ໙    LAO DIGIT NINE                           9      9      9      DecimalDigitNumber
...
U+01F10B  🄋   DINGBAT CIRCLED SANS-SERIF DIGIT ZERO    0      -1     -1     OtherNumber
U+01F10C  🄌   DINGBAT NEGATIVE CIRCLED SANS-SERIF DIGIT ZERO 0      -1     -1     OtherNumber
U+01FBF0  🯰   SEGMENTED DIGIT ZERO                     -1     -1     -1     DecimalDigitNumber
U+01FBF1  🯱   SEGMENTED DIGIT ONE                      -1     -1     -1     DecimalDigitNumber
U+01FBF2  🯲   SEGMENTED DIGIT TWO                      -1     -1     -1     DecimalDigitNumber
U+01FBF3  🯳   SEGMENTED DIGIT THREE                    -1     -1     -1     DecimalDigitNumber
U+01FBF4  🯴   SEGMENTED DIGIT FOUR                     -1     -1     -1     DecimalDigitNumber
U+01FBF5  🯵   SEGMENTED DIGIT FIVE                     -1     -1     -1     DecimalDigitNumber
U+01FBF6  🯶   SEGMENTED DIGIT SIX                      -1     -1     -1     DecimalDigitNumber
U+01FBF7  🯷   SEGMENTED DIGIT SEVEN                    -1     -1     -1     DecimalDigitNumber
U+01FBF8  🯸   SEGMENTED DIGIT EIGHT                    -1     -1     -1     DecimalDigitNumber
U+01FBF9  🯹   SEGMENTED DIGIT NINE                     -1     -1     -1     DecimalDigitNumber

Answer 5

\d checks all Unicode, while [0-9] is limited to these 10 characters. If just 10 digits, you should use. Others I recommend using \d，Because writing less.