JSFiddle - React, Tailwind, and code Playground

by bvotcode

JavaScript

var str = 'F4, F5, F6, F7, F8, F9, F10, F11, F12, F13, F14, F15, F16, F17, F18, F19, F20';

const before_ = str.substring(0, str.indexOf(','));

console.log(before_);