Binary Search - Javascript

run.js

function banarySearch(key, arr, min, max, callBack) {
  if (min >= max) {
    return undefined;
  }
  const midIndex = parseInt(min + (max - min) / 2, 0.0);
  const result = callBack(arr[midIndex]);
  if (result > key) {
    return banarySearch(key, arr, min, midIndex, callBack);
  } else if (result < key) {
    return banarySearch(key, arr, midIndex + 1, max, callBack);
  } else {
    return midIndex;
  }
}

Usage

class Struct {
  constructor(id) {
    this.id = id;
  }
}

let listStructs = [
  new Struct(0),
  new Struct(1),
  new Struct(2),
  new Struct(3),
  new Struct(4),
  new Struct(5),
  new Struct(6),
  new Struct(7),
  new Struct(8),
  new Struct(9),
  new Struct(10),
  new Struct(11)
];

let result = banarySearch(
  1,
  listStructs,
  0,
  listStructs.length,
  function callBack(item) {
    return item.id;
  }
);

console.log(listStructs[result]);