删除随机符号之间的文本 - JavaScript

Question

I have this input text with a pattern * + [*]*[/*] + * :

Input: [tag]random text EXCLUDE[/tag] text here

Output: text here

Input: [tag_1]another random text EXCLUDE[/tag_1] another text here

Output: another text here

Input: [tag_1]another random text EXCLUDE[/tag_1] another text here [tag_1] another random text EXCLUDE[/tag_1] text [tag_3]another random text EXCLUDE[/tag_3]

Output: another text here text

What I want is to remove the text, between [*] and [/*] , like replacing it with ''.

The problem is that the symbols, between [] are random, but if there is an open [*] , there is and closed [/*] , without nesting.

Answer 1

This should do the trick:

let OUTPUT = INPUT
    .split('[')
    .filter(s => s.indexOf(']') == -1 || s.startsWith('/'))
    .map(s => s
        .split(']')
        .reverse()[0])
    .join('')

The main point is, the text inside [] doesn't actually matter, all we need are the square brackets to act as "anchors".

I tried and failed to write a concise step-by-step explanation... My suggestions is to copy-paste the code in a console, feed it some data and watch what comes out of each step, it's self-evident.

Answer 2

This looks like a nice job for regular expressions:

 const theStrings = [ '[tag]random text EXCLUDE[/tag] text here', '[tag_1]another random text EXCLUDE[/tag_1] another text here', '[random]another random text EXCLUDE[/random] another text here', '[this]is not to be [/filtered] as they don\'t match', '[tag_1]another random text EXCLUDE[/tag_1] another text here [tag_1] another random text EXCLUDE[/tag_1] text [tag_3]another random text EXCLUDE[/tag_3]' ] let replaced = ''; let prev_len = 0; theStrings.forEach(str => { replaced = str; do { prev_len = replaced.length; replaced = replaced.replace(/\[(.*)\].*?\[\/\1\](.*)/,'$2') } while (replaced.length < prev_len); console.log("before:",str,"\nafter:", replaced) } )

https://regex101.com/r/cE6NZm/1

basically it's capturing anything between [this] and [/this] (notice they are the same but the second one has to be preceded by a / ) and letting out that portion of the string