const doSearch = function (array, targetValue) {
  let minIndex = 0;
  let maxIndex = array.length - 1;
  let guessIndex;

  console.log(minIndex,maxIndex,guessIndex)

  while(maxIndex >= minIndex){
    guessIndex = Math.floor((maxIndex+minIndex)/2)
    console.log({minIndex, max, guessIndex});
    console.log('==========');
    console.log(array[guessIndex], targetValue);
    console.log("==========");
    if(array[guessIndex] === targetValue) {
      return guessIndex
    } else if ( array[guessIndex] < targetValue ) {
      minIndex = guessIndex + 1;
    } else {
      max = guessIndex -1
    }
  }

  return -1 // value not present
}

const array = [ 0, 8, 16, 20, 45, 65, 89, 100]

console.log(doSearch(array, 89))