Question

Given the value, I need to get the index or key which this value belongs in a Map without the need to iterate it. I’m using java.

Thanks

Answer 1

Guava has a BiMap, which is a bidirectional map (each key and each value are unique).

If you don’t waht to use an external library, you only have 2 options:

• use a plain HashMap and you will need to iterate over the keys
• use 2 hashmaps, one relating keys to values, and one relating values to keys (which in essence is what a bidirectional map does).