JSFiddle - React, Tailwind, and code Playground
by ipr101
JavaScript
var text = 'ACTION=UPDATE&DATATYPE=1&KEY=462&NUMBER=123.5263&SOMEID=845&IDTYPE=1&key=678';
var matches = text.match(/KEY=\d*|key=\d*/g);
for (i=0; i<matches.length; i++) {
alert(matches[i].toLowerCase().replace('key=',''));
}