How to directly initialize a HashMap (in a literal way)?

Question

How to directly initialize a HashMap (in a literal way)?

Is there some way of initializing a Java HashMap like this?:



Map<String,String> test = 

    new HashMap<String, String>{"test":"test","test":"test"};

What would be the correct syntax?
I am looking for the shortest/fastest way to put some "final/static" values in a map that never change and are known in advance when creating the Map.

dictionary java

4 years ago by akshay1995

2 Answers

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**RoliMishra** · Answer 1 · 2021-05-11T13:53:40

For Java Version 9 or higher versions*

// this works for up to 10 elements:
Map<String, String> test1 = Map.of(
"a", "b",
"c", "d"
);

// this works for any number of elements:
import static java.util.Map.entry;
Map<String, String> test2 = Map.ofEntries(
entry("a", "b"),
entry("c", "d")
);

*For up to java 8 versions

Map<String, String> myMap = new HashMap<String, String>() {{

        put("a", "b");

        put("c", "d");

    }};

**kshitijrana14** · Answer 2 · 2021-05-13T13:52:16

kshitijrana14

This is one way.

Map<String, String> h = new HashMap<String, String>() {{

    put("a","b");

}};

4 years ago

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How to directly initialize a HashMap (in a literal way)?

2 Answers

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