Iterate through a HashMap [duplicate]

If you’re only interested in the keys, you can iterate through the keySet() of the map:
Map map = …;

for (String key : map.keySet()) {
// …
}

If you only need the values, use values():
for (Object value : map.values()) {
// …
}

Finally, if you want both the key and value, use entrySet():
for (Map.Entry entry : map.entrySet()) {
String key = entry.getKey();
Object value = entry.getValue();
// …
}

One caveat: if you want to remove items mid-iteration, you’ll need to do so via an Iterator (see karim79’s answer). However, changing item values is OK (see Map.Entry).

Iterate through the entrySet() like so:
public static void printMap(Map mp) {
Iterator it = mp.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pair = (Map.Entry)it.next();
System.out.println(pair.getKey() + ” = ” + pair.getValue());
it.remove(); // avoids a ConcurrentModificationException
}
}

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