Find closest point in a Array

closestPoint.js

// num - number you're looking for
// pointArr - your array of points
// coordIdx - index of the coordinate you're searching for in the point
const closestPoint = (num, pointArr, coordIdx) => {
  let mid;
  let left = 0;
  let right = pointArr.length - 1;
  while (right - left > 1) {
    mid = Math.floor((left + right) / 2);
    if (pointArr[mid][coordIdx] < num) {
      left = mid;
    } else {
      right = mid;
    }
  }
  if (num - pointArr[left][coordIdx] <= pointArr[right][coordIdx] - num) {
    return left;
  }
  
  return pointArr[right];
}