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var memoizeId = require("memoize-id")

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memoize-id v1.0.0

Memoize a function by the identity of its arguments, using ES2015 Map

memoize-id npm

Memoize a function by the identity of its arguments, using ES2015 Map.


npm install memoize-id

Note: ES2015 Symbol and Map must be available where memoize-id is used. Refer to ECMAScript 6 compatibility table.


import memoize from 'memoize-id';
// or:
// const memoize = require('memoize-id').default;

let i = 0;
function fn(foo, bar, baz) {
  i += 1;
  return {
    args: [foo, bar, baz],
const memoizedFn = memoize(fn);

// 0
const v1 = memoizedFn('foo', 'bar', 'baz');
// { args: ['foo', 'bar', 'baz'], i: 1 }
// 1
const v2 = memoizedFn('foo', 'bar', 'baz');
// { args: ['foo', 'bar', 'baz'], i: 1 }
console.log(v1 === v2);
// true
// 1
const v3 = memoizedFn('foo', 'qux', 'baz');
// { args: ['foo', 'qux', 'baz'], i: 2 }
// 2
console.log(v1 == v3);
// false
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