Binary Search | TypeScript

main.ts

const binarySearch = (arr: number[], val: Number) => {
  let start: number = 0,
      end: number = arr.length - 1,
      middle: number

  while (start < end) {
    middle = Math.floor((+start + +end) / 2)

    if (val <= arr[middle]) {
      end = middle
    } else {
      start = middle + 1
    }
  }

  if (arr[start] === val) return start

  return -1
}

const arr: number[] = [1, 2, 3, 4, 5, 6, 7, 12, 124, 12312, 123122]

console.log(binarySearch(arr, 123122)) // 10
console.log(binarySearch(arr, 12312)) // 9
console.log(binarySearch(arr, 2)) // 1