Date: 2015jan3
Update: 2025sep26
Language: java
Q. Java: Convert a HashMap into an ArrayList
A. Here is a full example:
import java.util.HashMap;
import java.util.ArrayList;
class Demo {
public static void main(String []args) {
// If you have:
HashMap<String,Integer> h = new HashMap<String,Integer>();
h.put("one", 1);
h.put("two", 2);
// To convert the keys into an ArrayList:
ArrayList<String> keys = new ArrayList<String>(h.keySet());
System.out.println("keys ArrayList=" + keys);
// To convert the values into an ArrayList:
ArrayList<Integer> values = new ArrayList<Integer>(h.values());
System.out.println("values ArrayList=" + values);
}
}
Output:
keys ArrayList=[one, two]
values ArrayList=[1, 2]