Iterate through a HashMap [duplicate]

What’s the best way to iterate over the items in a HashMap?


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

Map<String, Object> 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<String, Object> 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).

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