Does “\d” in regex mean a digit?

Question

I found that in 123, \\d matches 1 and 3 but not 2. I was wondering if \\d matches a digit sati

Answer 1

Info regarding .NET / C#:

Decimal digit character: \d \d matches any decimal digit. It is equivalent to the \p{Nd} regular expression pattern, which includes the standard decimal digits 0-9 as well as the decimal digits of a number of other character sets.

If ECMAScript-compliant behavior is specified, \d is equivalent to [0-9]. For information on ECMAScript regular expressions, see the "ECMAScript Matching Behavior" section in Regular Expression Options.

Info: https://docs.microsoft.com/en-us/dotnet/standard/base-types/character-classes-in-regular-expressions#decimal-digit-character-d