Programming Concepts — Binary Search

Binary search is an efficient algorithm for finding a target value in a sorted array by repeatedly dividing the search range in half. Time complexity is O(log n).

function binarySearch(arr, target) {
  let left = 0, right = arr.length - 1;
  while (left <= right) {
    let mid = Math.floor((left + right) / 2);
    if (arr[mid] === target) return mid;
    if (arr[mid] < target) left = mid + 1;
    else right = mid - 1;
  }
  return -1;
}
console.log(binarySearch([1,2,3,4,5], 3)); // Output: 2