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A recursive binary search function
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function binarySearch(sortedArray, searchValue, minIndex, maxIndex) { | |
'use strict'; | |
var currentIndex; | |
var currentElement; | |
while (minIndex <= maxIndex) { | |
// Find the value of the middle of the array | |
var middleIndex = (minIndex + maxIndex) / 2 | 0; | |
currentElement = sortedArray[middleIndex]; | |
// It's the same as the value in the middle - we can return! | |
if (currentElement === searchValue) | |
{ | |
return middleIndex; | |
} | |
// Is the value less than the value in the middle of the array | |
if (currentElement < searchValue) { | |
return binarySearch(sortedArray, searchValue, middleIndex + 1, maxIndex); | |
} | |
// Is the value greater than the value in the middle of the array | |
if (currentElement > searchValue) { | |
return binarySearch(sortedArray, searchValue, minIndex, middleIndex - 1); | |
} | |
} | |
return -1; | |
} | |
// The array with all of our numbers | |
var sortedArray = [1,2,4,5,10,12,44,89,99,304]; | |
// The value we are looking for in the array | |
var valueToFind = 89; | |
// The starting index point in the array | |
var minIndex = 0; | |
// The full size of the array | |
var maxIndex = sortedArray.length - 1; | |
var result = binarySearch(sortedArray, valueToFind, minIndex, maxIndex); | |
console.log('The index position is: ', result); | |
console.log('The value is: ', sortedArray[result]); |
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