# Installation > `npm install --save @types/deep-eql` # Summary This package contains type definitions for deep-eql (https://github.com/chaijs/deep-eql). # Details Files were exported from https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/deep-eql. ## [index.d.ts](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/deep-eql/index.d.ts) ````ts declare namespace deepEqual { /** * Memoization class used to speed up comparison. */ class MemoizeMap extends WeakMap {} interface DeepEqualOptions { /** * Override default algorithm, determining custom equality. */ comparator?: (leftHandOperand: T1, rightHandOperand: T2) => boolean | null; /** * Provide a custom memoization object which will cache the results of * complex objects for a speed boost. * * By passing `false` you can disable memoization, but this will cause circular * references to blow the stack. */ memoize?: MemoizeMap | false; } } /** * Assert deeply nested sameValue equality between two objects of any type. * * @param leftHandOperand * @param rightHandOperand * @param [options] Additional options * @return equal match */ declare function deepEqual( leftHandOperand: T1, rightHandOperand: T2, options?: deepEqual.DeepEqualOptions, ): boolean; export = deepEqual; ```` ### Additional Details * Last updated: Mon, 06 Nov 2023 22:41:05 GMT * Dependencies: none # Credits These definitions were written by [Rodrigo Pietnechuk](https://github.com/ghnoob).