---
title: "MTExpression | Mobile sdk | Mobile sdk ios | Ios"
description: "Helper to construct common style expressions without raw strings."
---

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# MTExpression

```
public enum MTExpression
```

Helper to construct common style expressions without raw strings.

-   `[get(_:)](#/s:11MapTilerSDK12MTExpressionO3getyAA15MTPropertyValueOSSFZ)`
    
    \[“get”, key\]
    
    #### Declaration
    
    Swift
    
    ```
    public static func get(_ key: String) -> MTPropertyValue
    ```
    
-   `[get(_:)](#/s:11MapTilerSDK12MTExpressionO3getyAA15MTPropertyValueOAA12MTFeatureKeyOFZ)`
    
    \[“get”, key\]
    
    #### Declaration
    
    Swift
    
    ```
    public static func get(_ key: MTFeatureKey) -> MTPropertyValue
    ```
    
-   `[toString(_:)](#/s:11MapTilerSDK12MTExpressionO8toStringyAA15MTPropertyValueOAFFZ)`
    
    \[“to-string”, expr\]
    
    #### Declaration
    
    Swift
    
    ```
    public static func toString(_ value: MTPropertyValue) -> MTPropertyValue
    ```
    
-   `[step(input:default:stops:)](#/s:11MapTilerSDK12MTExpressionO4step5input7default5stopsAA15MTPropertyValueOAI_AISaySd_AItGtFZ)`
    
    step expression builder: \[“step”, input, default, t1, v1, t2, v2, …\]
    
    #### Declaration
    
    Swift
    
    ```
    public static func step(
        input: MTPropertyValue,
        default defaultValue: MTPropertyValue,
        stops: [(Double, MTPropertyValue)]
    ) -> MTPropertyValue
    ```