- TIBCO BusinessEvents®
- Standard
- Collections
- Map
- Concurrent

# Collections.Map.Concurrent.putIfAbsent()

## Signature

`Object putIfAbsent ( Object map ,Object key ,Object value )`

## Domain

ACTION

## Description

If the specified key is not already associated with a value, associate it with the given value. The action is performed atomically.

## Parameters

Name | Type | Description
--- | --- | ---
`map` | `Object` | The concurrent map object
`key` | `Object` | key with which the specified value is to be associated.
`value` | `Object` | value to be associated with the specified key.

## Returns

Type | Description
--- | ---
`Object` | previous value associated with specified key, or null if there was no mapping for key. A null return can also indicate that the map previously associated null with the specified key, if the implementation supports null values.

## Cautions

none