IMap.Compute(Object, IBiFunction) Method

Reference

Definition

Namespace:: Java.Util

Assembly:: Mono.Android.dll

Important

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Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).

[Android.Runtime.Register("compute", "(Ljava/lang/Object;Ljava/util/function/BiFunction;)Ljava/lang/Object;", "GetCompute_Ljava_lang_Object_Ljava_util_function_BiFunction_Handler:Java.Util.IMap, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null", ApiSince=24)]
public virtual Java.Lang.Object? Compute (Java.Lang.Object? key, Java.Util.Functions.IBiFunction remappingFunction);

[<Android.Runtime.Register("compute", "(Ljava/lang/Object;Ljava/util/function/BiFunction;)Ljava/lang/Object;", "GetCompute_Ljava_lang_Object_Ljava_util_function_BiFunction_Handler:Java.Util.IMap, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null", ApiSince=24)>]
abstract member Compute : Java.Lang.Object * Java.Util.Functions.IBiFunction -> Java.Lang.Object
override this.Compute : Java.Lang.Object * Java.Util.Functions.IBiFunction -> Java.Lang.Object

Parameters

key: Object

key with which the specified value is to be associated

remappingFunction: IBiFunction

the remapping function to compute a value

Returns

Object

the new value associated with the specified key, or null if none

Attributes: RegisterAttribute

Remarks

Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping). For example, to either create or append a String msg to a value mapping:

{@code
            map.compute(key, (k, v) -> (v == null) ? msg : v.concat(msg))}

(Method #merge merge() is often simpler to use for such purposes.)

If the remapping function returns null, the mapping is removed (or remains absent if initially absent). If the remapping function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

The remapping function should not modify this map during computation.

Added in 1.8.

Java documentation for java.util.Map.compute(K, java.util.function.BiFunction<? super K, ? super V, ? extends V>).

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Applies to