# Add(TKey, TValue)

> Adds a new key-value pair.

## Definition

* **Type:** Method
* **Namespace:** [Unity.Collections](/engine/6000.7/script-reference/unity/collections.md)
* **Assembly:** UnityEngine.ManagedKernelModule

## Add(T, T)

```csharp
public void Add(TKey key, TValue item)
```

### Parameters

**** (T): The key to add.**** (T): The value to add.

### Remarks

If the key is already present, this method throws without modifying the hash map.