BinarySearch.js

/* Returns either the index of the location in the array,
  or -1 if the array did not contain the targetValue */
function doSearch(array, targetValue) {
	let min = 0;
	let max = array.length - 1;
  let guess;
   while(min < max + 1){
      guess = Math.floor((max + min) / 2);
        
      if(array[guess] === targetValue){
          return guess;
      }
      else if(array[guess] < targetValue){
          min = guess + 1;
      }
      else{max = guess - 1;}
   }
	return -1;
};

const primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 
		41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97];

let result = doSearch(primes, 73);
console.log("Found prime at index " + result);