# ST-REL-001 - Mismatched argument types

> **Rule ID**: `ST-REL-001`

**Rule ID**: `ST-REL-001`

**Scope**: Coded workflow

## Description

This rule ensures that the argument types of In/Out parameters are matching. For example, errors are highlighted when a `DataTable` is used as an output parameter for the `Execute` method, if the matching input parameter is a `DataSet`.

For instance, in the following code example, the same `isConnected` parameter is declared as `bool`, and then as an `int`. To resolve this, make sure the same type is used for the `isConnected` parameter both as input and output.

```
public (bool IsConnected, string Name) Execute(int IsConnected, int32 Name)
        {
            return (true, "Jade");
        }
```

## Recommendation

We recommend to make sure that the data types for In/Out arguments always match. If the method returns a tuple, such as in `public (bool IsConnected, string Name) Execute(int IsConnected, int32 Name)`, an In/Out argument must still be declared both before and after the method. In this case, `IsConnected` is the In/Out argument as it is declared twice.

On the other hand, when the method returns a single argument as in the example `public int Execute(int Output, int c)`, you can declare an In/Out argument by naming it `Output`. Naming any argument as `Output` treats it as an In/Out argument, even if it's only declared once in the method.