I am new to android. i know only core java.
I saw the declaration
ArrayList<ApplicationInfo> mAppInfo;
in Android sample project. Can anyone explain what is the meaning of above declaration.
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ArrayList of ApplicationInfo typePrince John Wesley– Prince John Wesley2011-11-07 06:35:46 +00:00Commented Nov 7, 2011 at 6:35
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There's nothing android specific here. It's a class member (presumably) declaration with generic type.slkorolev– slkorolev2011-11-07 06:37:47 +00:00Commented Nov 7, 2011 at 6:37
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4 Answers
This is core Java as well. Have a look at http://download.oracle.com/javase/1,5.0/docs/guide/language/generics.html
Also, it should most probably be:
List<ApplicationInfo> mAppInfo;
Comments
It's an ArrayList (a container type) which can hold objects of the ApplicationInfo type.
Comments
mAppInfo is an ArrayList of ApplicationInfo. (This list contains only ApplicationInfo objects.
It use a generic syntax to declare a reference mAppInfo. The name inside the angle bracket is a class name. For example, we can declare ArrayList<String> or ArrayList<Integer>.
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ArrayList is a Class from Java collection framework. You can use it in some ways like arrays but there are more advantages compared to normal arrays.
ApplicationInfo is the type of information you allowed to store in this arrayList. (Could also be String Integer, ... just no primitive Datatyps like int, float, ...)
mAppInfo is the name of the ArrayList.
Link to Java Oracle Documentation for more Information on ArrayLists:
https://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html
Good Luck with your work!
