Javascript how to identify a combination of letters and strip a portion of it

user_12705034 0
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Im very new to Regex . Right now im trynig to use regex to prepare my markup string before sending it to the database.

Here is an example string:

@[admin](user:3) Testing this string @[hellotessginal](user:4) Hey!

So far i am able to identify @[admin](user:3) the entire term here using /@\[(.*?)]\((.*?):(\d+)\)/g

But the next step forward is that i wish to remove the (user:3) leaving me with @[admin].

Hence the result of passing through the stripper function would be:

@[admin] Testing this string @[hellotessginal] Hey!

Please help!

reactjs javascript regex
3 Answers

You may use

s.replace(/(@\[[^\][]*])\([^()]*?:\d+\)/g, '$1')

See the regex demo. Details:

  • (@\[[^\][]*]) - Capturing group 1: @[, 0 or more digits other than [ and ] as many as possible and then ]
  • \( - a ( char
  • [^()]*? - 0 or more (but as few as possible) chars other than ( and )
  • : - a colon
  • \d+ - 1+ digits
  • \) - a ) char.

The $1 in the replacement pattern refers to the value captured in Group 1.

See the JavaScript demo:

const rx = /(@\[[^\][]*])\([^()]*?:\d+\)/g;
const remove_parens = (string, regex) => string.replace(regex, '$1');

let s = '@[admin](user:3) Testing this string @[hellotessginal](user:4) Hey!';
s = remove_parens(s, rx);
console.log(s);

user_38329700

Try this:

var str = "@[admin](user:3) Testing this string @[hellotessginal](user:4) Hey!";
str = str.replace(/ *\([^)]*\) */g, ' ');
console.log(str);

user_61742710

You can replace matches of the following regular expression with empty strings.

str.replace(/(?<=\@\[(.*?)\])\(.*?:\d+\)/g, ' ');

regex demo

I've assumed the strings for which "admin" and "user" are placeholders in the example cannot contain the characters in the string "()[]". If that's not the case please leave a comment and I will adjust the regex.

I've kept the first capture group on the assumption that it is needed for some unstated purpose. If it's not needed, remove it:

(?<=\@\[.*?\])\(.*?:\d+\)

There is of course no point creating a capture group for a substring that is to be replaced with an empty string.

Javascript's regex engine performs the following operations.

(?<=         : begin positive lookbehind
  \@\[       : match '@['
  (.*?)      : match 0+ chars, lazily, save to capture group 1
  \]         : match ']'
)            : end positive lookbehind
\(.*?:\d+\)  : match '(', 0+ chars, lazily, 1+ digits, ')'
user_2569700
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