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Modifying member of object in Map

开发者 https://www.devze.com 2023-02-05 12:45 出处:网络
If i create a class that has a member variable called \"testName\", and then create a few objects from this and place them all as values in a \"Map\". How can i iterate through this Map and modify the

If i create a class that has a member variable called "testName", and then create a few objects from this and place them all as values in a "Map". How can i iterate through this Map and modify the "testName" variable in each value Object?

In other words how can i access & modify members of an Object when 开发者_运维百科that object has been placed in a Map.


If the objects you want modified are all values in the map, and you don't want to change the mappings from key to value, you can iterate through a collection of just the map's values:

Collection< ValueType > vals = map.values();
for (ValueType val : vals) {
    val.testName = ...
}


You have to iterate through each of the entries of the Map and modify the name. See here for example on how to iterate through the Map


A Map is not by itself iterable, but you can get the keySet from the map via the keySet() method and since this is a Set is iterable (implements the Iterable interface). Iterate through the keySet obtaining each value from the Map via its get method and make the changes you desire.

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