how to print the map in java
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.stream.Stream;
class MapUtil
{
// Program to print all keys present in the Map using keySet() in Java
public static void main (String[] args)
{
Map<Integer, String> map = new HashMap<>();
map.put(1, "One");
map.put(2, "Two");
// 1. using Iterator
Iterator<Integer> itr = map.keySet().iterator();
while (itr.hasNext()) {
System.out.println(itr.next());
}
// 2. For-each Loop
for (Integer key : map.keySet()) {
System.out.println(key);
}
// 3. Java 8 - Collection.iterator() + Iterator.forEachRemaining()
map.keySet().iterator()
.forEachRemaining(System.out::println);
// 4. Java 8 - Collection.stream() + Stream.forEach()
map.keySet().stream()
.forEach(System.out::println);
// Java 8 - Stream.of() + Collection.toArray() + Stream.forEach()
Stream.of(map.keySet().toArray())
.forEach(System.out::println);
// 5. Convert to String
System.out.println(map.keySet().toString());
// Java 8
Stream.of(map.keySet().toString())
.forEach(System.out::println);
}
}