module.exports = function (array, number) {

return (function searchNumber (left, right) {

var center = left + Math.floor((right - left) / 2);

// If the numbers match, return the center index.

if (array[center] === number) { return center; }

// If the left position is the same as the center position, return -1.

if (left === center) { return -1; }

// When the current number is larger than the search input, recurse

// moving the left and right indexes to the search area.

if (array[center] > number) {

return searchNumber(left, center);

}

// When the current number is smaller move the search parameters to the

// right.

if (array[center] < number) {

return searchNumber(center, right);

}

return -1;

})(0, array.length);

};