---
title: "Property | 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.

# Interface Property<T, R>

interface Property<[T](#t), [R](#r)\> {  
    [specification](#specification): [StylePropertySpecification](https://docs.maptiler.com/sdk-js/api-reference/types/StylePropertySpecification/);  
    [interpolate](#interpolate-1)(a: [R](#r), b: [R](#r), t: number): [R](#r);  
    [possiblyEvaluate](#possiblyevaluate-1)(  
        value: [PropertyValue](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.PropertyValue/)<[T](#t), [R](#r)\>,  
        parameters: [EvaluationParameters](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.EvaluationParameters/),  
        canonical?: [CanonicalTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.CanonicalTileID/),  
        availableImages?: string\[\],  
    ): [R](#r);  
}

#### Type Parameters

-   T
-   R

#### Implemented by

-   [ColorRampProperty](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.ColorRampProperty/)
-   [CrossFadedProperty](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.CrossFadedProperty/)
-   [DataConstantProperty](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.DataConstantProperty/)
-   [DataDrivenProperty](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.DataDrivenProperty/)
-   [LightPositionProperty](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.LightPositionProperty/)

##### Index

### Properties[](#properties)

[specification](#specification)

### Methods[](#methods)

[interpolate](#interpolate) [possiblyEvaluate](#possiblyevaluate)

## Properties[](#properties-1)

### specification[](#specification)

specification: [StylePropertySpecification](https://docs.maptiler.com/sdk-js/api-reference/types/StylePropertySpecification/)

## Methods[](#methods-1)

### interpolate[](#interpolate)

-   interpolate(a: [R](#r), b: [R](#r), t: number): [R](#r)[](#interpolate-1)
    
    #### Parameters
    
    -   a: [R](#r)
    -   b: [R](#r)
    -   t: number
    
    #### Returns [R](#r)
    

### possiblyEvaluate[](#possiblyevaluate)

-   possiblyEvaluate(  
        value: [PropertyValue](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.PropertyValue/)<[T](#t), [R](#r)\>,  
        parameters: [EvaluationParameters](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.EvaluationParameters/),  
        canonical?: [CanonicalTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.CanonicalTileID/),  
        availableImages?: string\[\],  
    ): [R](#r)[](#possiblyevaluate-1)
    
    #### Parameters
    
    -   value: [PropertyValue](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.PropertyValue/)<[T](#t), [R](#r)\>
    -   parameters: [EvaluationParameters](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.EvaluationParameters/)
    -   `Optional`canonical: [CanonicalTileID](https://docs.maptiler.com/sdk-js/api-reference/classes/Externals.CanonicalTileID/)
    -   `Optional`availableImages: string\[\]
    
    #### Returns [R](#r)