Match against property in array of objects without using For loop

Asked Jul 24 '14 at 18:13

Active Jul 24 '14 at 18:18

Viewed 38 times

I have an array of objects TimeTrial. Each TimeTrial object contains the time to run the trial, the distance, and the person who ran it.

Given a person, I want to see whether the person has run any of the trials in the list. If the list was just a list of people, I would write trials.contains(person).

In Python, I would just do if person in map(lambda trial: trial["runner"], trials). But this functionality doesn't seem too be available in Java.

Is there a simple way to do this without writing a For loop?

asked Jul 24 '14 at 18:13

Andrew Latham

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Which version of Java are you using? – Farhad Alizadeh Noori Jul 24 '14 at 18:19
why the requirement to not use the most appropriate thing? you realize that `map` and equivlent methods iterate under the covers right? same difference, syntactic sugar not withstanding – Jul 24 '14 at 18:21
No way this is a duplicate -.- He wants something close to lambda expressions.. in this case, filter. The other topic you're referencing as duplicate is something else (sorting). – Breno Inojosa Jul 24 '14 at 18:21
Use this: List timeTrials = ... Stream timeTrialsPersonHasRan = timeTrials.stream().filter(t -> t.wasRanBy(personId)); – Breno Inojosa Jul 24 '14 at 18:22
@BrenoInojosa why not provide this as an answer? – Farhad Alizadeh Noori Jul 24 '14 at 18:23
@Farhad : because this topic is now closed T.T – Breno Inojosa Jul 24 '14 at 18:24
Use a List and the `contains` method. Or, if one insists on using a vanilla array, write a recursive method. – Hot Licks Jul 24 '14 at 18:28
Well, anyway, I posted my answer there, in the other topic. – Breno Inojosa Jul 24 '14 at 18:31

Match against property in array of objects without using For loop

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