Metacharacters vs Character ranges in Javascript Regex

Question

I see more often that people use: [0-9] instead of \d and [A-Za-z0-9_] instead of \w

Is there some inconsistencies between browsers or other drawbacks when using metacharacters? Should i use character ranges instead of corresponding metacharacters?

Answer 1

No known inconsistencies, but two possible reasons.

First, both \d and \w mean different things in different RegExp implementations. Quoting regular-expressions.info:

Since certain character classes are used often, a series of shorthand character classes are available. \d is short for [0-9]. In most flavors that support Unicode, \d includes all digits from all scripts. Notable exceptions are Java, JavaScript, and PCRE. These Unicode flavors match only ASCII digits with \d.

So, yes, JavaScript is safe in this regard - but if you mostly deal with other implementations (like C# and Python3), you might just not be aware of this.

Second, some developers might prefer [0-9] to \d just because, well, explicit is better than implicit.