How to put/get values into/from Nested HashMap

Question

I want to create a nested HashMap that will take two keys of type float and give out value of type Integer.

 public static HashMap<Float, HashMap<Float, Integer>> hashX = new HashMap<Float,HashMap<Float, Integer>>();

Is there a simple method of putting/getting the values like an ordinary HashMap i.e.

  hashX.put(key, value);
  hashX.get(key);

or is it a more complicated method that must be used? I have searched around the web for a solution but am finding it tough to find a solution that applies to me. Any help would be appreciated!

Answer 1

Map<Float, Map<Float, Integer>> map = new HashMap<>();

map.put(.0F, new HashMap(){{put(.0F,0);}});
map.put(.1F, new HashMap(){{put(.1F,1);}});

map.get(.0F).get(.0F);

Answer 2

You have to get() the nested map out of the outer map and call can call put() and get() on it

float x = 1.0F;
HashMap<Float, Integer> innerMap = hashX.get(x);
if (innerMap == null) {
    hashX.put(x, innerMap = new HashMap<>()); // Java version >= 1.7
}
innerMap.put(2.0F, 5);