Java – Map Iterate Example

[code lang=”java”]import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class LoopMap {

public static void main(String[] args) {

// initial a Map
Map<String, String> map = new HashMap<String, String>();
map.put("1", "Jan");
map.put("2", "Feb");
map.put("3", "Mar");
map.put("4", "Apr");
map.put("5", "May");
map.put("6", "Jun");

System.out.println("Example 1…");
// Map -< Set -> Iterator -< Map.Entry -> troublesome
Iterator iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry mapEntry = (Map.Entry) iterator.next();
System.out.println("The key is: " + mapEntry.getKey() + ",value is :" + mapEntry.getValue());
}

System.out.println("Example 2…");
// more elegant way
for (Map.Entry<String, String> entry : map.entrySet()) {
System.out.println("Key : " + entry.getKey() + " Value : " + entry.getValue());
}

System.out.println("Example 3…");
// weired way, but work anyway
for (Object key : map.keySet()) {
System.out.println("Key : " + key.toString() + " Value : " + map.get(key));
}

}

}[/code]


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