Map.Entry

[AJ sisodia]

can't understand how to make use of "Map.Entry".Pls help by giving simple examples.

[Jesper de Jong]

Can you please be more specific about what you don't understand? Do you have some code and it doesn't work? If so, post the code, so that we can tell you what's wrong with it. Here's a simple example, iterating a Map:

Map map = new HashMap();
// ...fill the map
 
// Iterate the map
Iterator i = map.entrySet().iterator();
while (i.next()) {
    Map.Entry e = (Map.Entry) i.next();
    System.out.println("key=" + e.getKey() + ", value=" + e.getValue());
}

[Jeff Albertson]

import java.util.*;
 
public class Test {
public static void main(String[] args) {
example_pre_1_5();
example();
}
 
static void example_pre_1_5() {
Map m = new TreeMap();
m.put("A","apple" );
m.put("B","banana");
m.put("C","cherry");
 
//alter every value using its key
for(Iterator i = m.entrySet().iterator(); i.hasNext(); ) {
Map.Entry e = (Map.Entry) i.next();
e.setValue(e.getKey() + " is for " + e.getValue());
}
 
System.out.println(m);
}
 
static void example() {
Map<String, String> m = new TreeMap<String, String>();
m.put("A","apple" );
m.put("B","banana");
m.put("C","cherry");
 
//alter every value using its key
for(Map.Entry<String, String> e : m.entrySet())
e.setValue(e.getKey() + " is for " + e.getValue());
 
System.out.println(m);
}
}