Java Map Get Key. In this tutorial well discuss how to get the first key-value pair from a HashMap without knowing the key. If you want to get HashMap value using a key you can use the get method and provide the key for which you want to fetch the value.
In this tutorial well discuss how to get the first key-value pair from a HashMap without knowing the key. A Map cannot contain duplicate keys and each key can map to at most one value. But what if you want to get key from a value.
However BidiMap imposes a 11 relationship between its keys and values.
In Java we can get the keys and values via mapentrySet. Each key can map to at most one value. If you want to get HashMap value using a key you can use the get method and provide the key for which you want to fetch the value. From the example below basically we have a.
