collections Archives - Page 9 of 12

How can I convert List to int[] in Java? [duplicate]

This question already has answers here: How to convert an ArrayList containing Integers to primitive int array? (19 answers) Closed 3 years ago. ...

April 27, 2022
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Easiest way to convert a List to a Set in Java

What is the easiest way to convert a List to a Set in Java? 17 s 17 Set<Foo> foo = new HashSet<Foo>(myList);

April 27, 2022
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How can I turn a List of Lists into a List in Java 8?

If I have a List<List<Object>>, how can I turn that into a List<Object> that contains all the objects in the same iteration order ...

April 25, 2022
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How to filter a Java Collection (based on predicate)?

I want to filter a java.util.Collection based on a predicate. 29 s 29 Java 8 (2014) solves this problem using streams and lambdas ...

April 25, 2022
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How to convert an Array to a Set in Java

I would like to convert an array to a Set in Java. There are some obvious ways of doing this (i.e. with a ...

April 22, 2022
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How to initialize HashSet values by construction?

I need to create a Set with initial values. Set<String> h = new HashSet<String>(); h.add("a"); h.add("b"); Is there a way to do this ...

April 19, 2022
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Efficiency of Java “Double Brace Initialization”?

In Hidden Features of Java the top answer mentions Double Brace Initialization, with a very enticing syntax: Set<String> flavors = new HashSet<String>() {{ ...

April 18, 2022
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Efficiency of Java “Double Brace Initialization”?

In Hidden Features of Java the top answer mentions Double Brace Initialization, with a very enticing syntax: Set<String> flavors = new HashSet<String>() {{ ...

April 18, 2022
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