---
title: "Evaluate | JavaScript maps SDK"
description: "Documentation for MapTiler SDK"
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Type Alias Evaluate

Evaluate: (b: [EvaluationContext](https://docs.maptiler.com/sdk-js/api-reference/classes/EvaluationContext/), a: [Expression](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Expression/)\[\]) \=> [Value](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.Value/)

#### Type Declaration

-   -   (b: [EvaluationContext](https://docs.maptiler.com/sdk-js/api-reference/classes/EvaluationContext/), a: [Expression](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Expression/)\[\]): [Value](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.Value/)
    -   #### Parameters
        
        -   b: [EvaluationContext](https://docs.maptiler.com/sdk-js/api-reference/classes/EvaluationContext/)
        -   a: [Expression](https://docs.maptiler.com/sdk-js/api-reference/interfaces/Expression/)\[\]
        
        #### Returns [Value](https://docs.maptiler.com/sdk-js/api-reference/types/Externals.Value/)