java for map

To iterate over the keys and values in a Map object in Java, you can use a for loop in combination with the Map object's entrySet() method, which returns a Set view of the mappings contained in the Map.

Here's an example of how to do it:

import java.util.Map;
import java.util.Set;

public class Main {
  public static void main(String[] args) {
    Map<String, Integer> map = Map.of("a", 1, "b", 2, "c", 3);

    // Iterate over the entries in the map
    for (Map.Entry<String, Integer> entry : map.entrySet()) {
      String key = entry.getKey();
      Integer value = entry.getValue();
      System.out.println(key + ": " + value);
    }
  }
}

This code creates a Map object with three key-value pairs and then uses a for loop to iterate over the entries in the map. The loop variable entry is a Map.Entry object that represents a single key-value pair in the map. The entrySet() method returns a Set view of the map's entries, which allows you to use the for-each loop to iterate over the entries.

Inside the loop, the getKey() and getValue() methods of the Map.Entry object are used to retrieve the key and value of the current entry.

You can use a similar approach to iterate over the keys or values in a Map object, using the keySet() or values() methods instead of the entrySet() method.