About Question enthuware.ocpjp.v8.2.1834 :

[Danny Sheridan]

Hi there

To achieve the same as the Java 7 process method in the question
would the new process method in the first answer not need another line like...

Code: Select all

groupedValues.get(name).add(value);

[admin]

No, because the line groupedValues.computeIfAbsent(name, (a)->new ArrayList<Double>()), does same job that groupedValues.get(), is doing in the Java 7 version. This call returns a list and then a call to add is chained to that list.
groupedValues.computeIfAbsent(name, (a)->new ArrayList<Double>()).add(value);

HTH,
Paul.

[Danny Sheridan]

Great stuff
Thanks for the clear explanation

[clhizerti]

This question took me a lot of time!
I read the answer as:
computeIfAbsent(name, (a)->new ArrayList<Double>().add(value))
and therefore thought the answer to the question was false.