正则表达式获取字符和空格之间的字符串并排除第一个分隔符

Question

In the following text what Regex (Javascript) would match "user" (user is a random name), excluding the "@" character?

I want to tag this @user here
and this @user
@user

I have looked at the following solutions and made the following regexes that did not work

RegEx pattern to match a string between two characters, but exclude the characters

\@(.*)\s

Regular Expression to find a string included between two characters while EXCLUDING the delimiters

(?!\@)(.*?)(?=\s)

Regex: Matching a character and excluding it from the results?

^@[^\s]+

Finally I made this regex that works but returns "@user" instead of "user":

@[^\s\n]+

The Javascript used to execute the regex is:

string.match(/@[^\s\n]+/)

Answer 1

I see I need to post a clarification.

If one knows a pattern beforehand in JS, ie if you do not build a regex from separate variables, one should be using a RegExp literal notation (eg /<pattern>/<flag(s)> ).

In this case, you need a capturing group to get a submatch from a match that will start with a @ and go on until the next non-whitespace character. You cannot use String#match if you have multiple values inside one input string, as global regexps with that method lose the captured texts. You need to use RegExp#exec :

 var s = "I want to tag this @user here\\nand this @user\\n@user"; var arr = []; var re = /@(\\S+)\\b/g; while ((m=re.exec(s)) !== null) { arr.push(m[1]); } document.write(JSON.stringify(arr));

The regex I suggest is @(\\S+)\\b :

• @ - matches a literal @
• (\\S+) - matches and captures into Group 1 one or more non-whitespace characters that finish with
• \\b - word boundary (remove if you have Unicode letters inside the names).

Answer 2

If you execute it this way, it should work:

var str = "I want to tag this @user here";
var patt = new RegExp("@([^\\s\\n]+)");
var result = patt.exec(str)[1];