JSFiddle - React, Tailwind, and code Playground
JavaScript
chaine="234802!070!\r\n\
501250!001!\r\n\
503170-010!\r\n\
\r\n\
\r\n\
\r\n\
ddd!";
chaine=chaine.replace(/.(\r\n)?$/gm,"$1");
console.log(chaine)
chaine="234802!070!\r\n\
501250!001!\r\n\
503170-010!\r\n\
\r\n\
\r\n\
\r\n\
ddd!";
chaine=chaine.replace(/.(\r\n)?$/gm,"$1");
console.log(chaine)