Algorithm
Algorithm is quite simple. It can be done either recursively or iteratively:
1.       get the middle element;
2.       if the middle element equals to the searched value, the algorithm stops;
3.       otherwise, two cases are possible: 
o    searched value is less, than the middle element. In this case, go to the step 1 for the part of the array, before middle element.
o    searched value is greater, than the middle element. In this case, go to the step 1 for the part of the array, after middle element.