Question

How to convert map keys to a Stream in Java

Answer 1

import java.util.*; 
import java.util.stream.*; 

public class MyClass {
    public static void main(String args[]) {
        Map<Integer, String> map = new HashMap<>(); 
  
        map.put(1, "java"); 
        map.put(2, "c"); 
        map.put(3, "c++"); 
        map.put(4, "php"); 
  
        Stream<Integer> stream = map.keySet().stream(); 
                        
        System.out.println(Arrays.toString(stream.toArray()));           
    }
}



/*
run:

[1, 2, 3, 4]

*/

 

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