I have this string:

saidogAngry Kappa saidogAngry saidogAngry ResidentSleeper ResidentSleeper

I need to replace parts of this string with rep based on an array of this kind:

const eleArray = [{
  "start": "0",
  "end": "10",
  "rep": "63f5ce1593c142a09d714b34e1938990"
}, {
  "start": "12",
  "end": "16",
  "rep": "25"
}, {
  "start": "18",
  "end": "28",
  "rep": "63f5ce1593c142a09d714b34e1938990"
}, {
  "start": "30",
  "end": "40",
  "rep": "63f5ce1593c142a09d714b34e1938990"
}, {
  "start": "42",
  "end": "56",
  "rep": "245"
}, {
  "start": "58",
  "end": "72",
  "rep": "245"
}]

The problem is that after the first replace, all other indexes are altered.

My initial idea was to split it in single sections and then remove/replace them

const msgArray = [];
let lastIndex = 0;
eleArray.forEach(ele => {
  msgArray.push(message.slice(Number(lastIndex), Number(ele.start)));
  // msgArray.push(message.slice(Number(ele.start), Number(ele.end+1)));
  msgArray.push(ele.rep);
  lastIndex = Number(ele.end)+1;
});
console.log(msgArray.join('');

Is there a simpler or a more optimized way? I need to have the best best performance out of it because I’m creating a text stream with a big quantity of messages.