const regex = /([0-9]{4}.G[0-9]{2}(?: [0-9]{4}.G[0-9]{2})* |( )(?=Jednostki))/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('([0-9]{4}.G[0-9]{2}(?: [0-9]{4}.G[0-9]{2})* |( )(?=Jednostki))', 'gm')
const str = `Dane osobowe po zmianie (dopisane): Surname1 Name1 (RYSZARD, EUGENIA) Zam. 99-100 Muczyn (Geod) 6A, Płeć: K, PESEL: 99945104321 Jednostki Rejestrowe osoby (w gminie): 0001.G16 0002.G56 Surname2 Name2 (ANDRZEJ, AGNIESZKA) Zam. 99-100 Muczyn (Geod) 4A, Płeć: K Jednostki Rejestrowe osoby (w gminie): 0001.G16 0001.G07 0001.G43 Surname1 Name1 Name2 (ANDRZEJ, AGNIESZKA) Zam. 99-100 MUCZYN (Geod) 4A, Płeć: M Jednostki Rejestrowe osoby (w gminie): 0001.G16`;
const subst = `\0\n`;
// 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