JSFiddle - React, Tailwind, and code Playground

JavaScript

const minMeetingRooms = (intervals) => {
  let startList = [];
  let endList = [];
  let endPos = 0;
  let rooms = 0;
  for (let i = 0; i < intervals.length; i++) {
    startList.push(intervals[i][0]);
    endList.push(intervals[i][1]);
  }
  startList.sort((a, b) => a - b);
  endList.sort((a, b) => a - b);
  for (let i = 0; i < intervals.length; i++) {
    if (startList[i] < endList[endPos]) {
      rooms++;
    } else {
      endPos++;
    }
  }
  return rooms;
};

console.log(minMeetingRooms([
  [7, 10],
  [2, 4]
]));