@loopback/docs/site/apidocs/context.resolvemap.md

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---
lang: en
title: 'API docs: context.resolvemap'
keywords: LoopBack 4.0, LoopBack 4, Node.js, TypeScript, OpenAPI
sidebar: lb4_sidebar
editurl: https://github.com/loopbackio/loopback-next/tree/master/packages/context
permalink: /doc/en/lb4/apidocs.context.resolvemap.html
---

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[Home](./index.md) &gt; [@loopback/context](./context.md) &gt; [resolveMap](./context.resolvemap.md)

## resolveMap() function

Resolve entries of an object into a new object with the same keys. If one or more entries of the source object are resolved to a promise by the `resolver` function, this method returns a promise which will be resolved to the new object with fully resolved entries.

**Signature:**

```typescript
export declare function resolveMap<T, V>(map: MapObject<T>, resolver: (val: T, key: string, values: MapObject<T>) => ValueOrPromise<V>): ValueOrPromise<MapObject<V>>;
```

## Parameters

<table><thead><tr><th>

Parameter


</th><th>

Type


</th><th>

Description


</th></tr></thead>
<tbody><tr><td markdown="1">

map


</td><td markdown="1">

[MapObject](./context.mapobject.md)<!-- -->&lt;T&gt;


</td><td markdown="1">

The original object containing the source entries


</td></tr>
<tr><td markdown="1">

resolver


</td><td markdown="1">

(val: T, key: string, values: [MapObject](./context.mapobject.md)<!-- -->&lt;T&gt;) =&gt; [ValueOrPromise](./context.valueorpromise.md)<!-- -->&lt;V&gt;


</td><td markdown="1">

A function resolves an entry to a value or promise. It will be invoked with the property value, the property name, and the source object.


</td></tr>
</tbody></table>

**Returns:**

[ValueOrPromise](./context.valueorpromise.md)<!-- -->&lt;[MapObject](./context.mapobject.md)<!-- -->&lt;V&gt;&gt;

## Example

- Example 1: resolve all entries synchronously

```ts
const result = resolveMap({a: 'x', b: 'y'}, v => v.toUpperCase());
```
The `result` will be `{a: 'X', b: 'Y'}`<!-- -->.

- Example 2: resolve one or more entries asynchronously

```ts
const result = resolveMap({a: 'x', b: 'y'}, v =>
  Promise.resolve(v.toUpperCase()),
);
```
The `result` will be a promise of `{a: 'X', b: 'Y'}`<!-- -->.