const regex = new RegExp('(?|(e)(pisodes?)|(c)(hapters?)|(c)(hs?)|(e)(ps?)|(c)(s?)|(e)(s?)|()())\\s*((\\d+(?:\\.\\d+)?(?:[A-Z]\\b)?)(?:\\s*(?:[,&+-]|and)\\s*(?:(?:e(?:pisodes?)|c(?:hapters?)|c(?:hs?)|e(?:ps?)|c(?:s?)|e(?:s?)|)\\s*)?(?4))*)', 'gui')
const str = `chapter 2A Hello
chapter 2AHello
text chapter 25.6 text
// c~25.6
text chapters 23, 24, 25 text
// c~23-25
text chapter 23, 25 text
// c~23 & 25
text chapter 23 & 24 & 25 text
// c~23-25
text c25.5-30 text
// c~25.5-30
text c99-c102 text
// c~99-102
text chapter 1 - 3 text
// c~1-3
33 text chapter 1, 2 text 3
// c~1-2
chapter 25.6 & chapter 29
// c~25.6 & 29
chapter 25+c26
// c~25-26
chapter 25 + 26 + 27
// c~25-27
chapter 10.4C
= c~10.4 part 3
chapter 2B
= c~2 part 2`;
const subst = ``;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions