[Home](./index.md) > [@essex/toolbox](./toolbox.md) > [binarySearch](./toolbox.binarysearch.md) ## binarySearch() function Performs a binary search on the given array Signature: ```typescript export declare function binarySearch(array: T[], item: T, compare?: typeof DEFAULT_COMPARE): number; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | array | T\[\] | The array of numbers to search | | item | T | The item to look for | | compare | typeof DEFAULT\_COMPARE | (Optional) | Returns: number index of found item