binarySearch.js

function binarySearch(array, value) {
  let i = 0;
  let j = array.length - 1;
  while(i <= j) {
    const middle = Math.floor((j + i) / 2);
    if(array[middle] === value) return middle;
    if(array[middle] > value) j = middle - 1;
    else i = middle + 1;
    
  }

  return -1;
}


console.log(binarySearch([3,5,7,10,18], 10)); // 3
console.log(binarySearch([3,5,7,10,18], 0)); // -1
console.log(binarySearch([3,5,7,10,18], 5)); // 2
console.log(binarySearch([], 10)); // -1
console.log(binarySearch([10], 10)); // 0