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Recompute Values

Using compute() Method.

  1. compute() - Computes a new value using the specified function. It then associates the computed value to the specified key.
  2. computeIfAbsent() - If the specified key is not mapped to any value, the method will compute a new value using the specified function. It then associates the new value with the key.
  3. computeIfPresent() - If the specified key is already mapped to any value, this method will compute a new value using the specified function. It then associates the new value with the key.


\begin{lstlisting} import java.util.HashMap; \par class Main { public static vo... ...println(''HashMap using computeIfPresent(): '' + numbers); } } \end{lstlisting}

Output


\begin{lstlisting} Original HashMap : {Second =2 , First =1} HashMap using compu... ...Map using computeIfPresent () : {Second =6, First =3, three =5} \end{lstlisting}