JSFiddle - React, Tailwind, and code Playground

JavaScript

var x1 = 'var x = "sdfsfsdf"';
var x2 = 'function(a){var b=document.createElement("script");';

var p = /(^|;|{)\s*(var\s+)?(\S+)\s*=\s*['"][^'"]*['"]\s*(}|;|$)/i;

console.log(x1.match(p));
console.log(x2.match(p));