How do I cast a list of objects?

How do I cast a list of objects?

you can always cast any object to any type by up-casting it to Object first. in your case: (List)(Object)list; you must be sure that at runtime the list contains nothing but Customer objects.

Can a list contain any type of object?

Lists can contain any arbitrary objects. List elements can be accessed by index. Lists are mutable.

Can we assign list of String into a list of object variable?

7 Answers. Pass the List<String> as a parameter to the constructor of a new ArrayList . List objectList = new ArrayList(stringList); The constructor takes a Collection , but List is a subinterface of Collection , so you can just use the List .

Can convert an object into a list?

Correct Option: B. singletonList() returns the object as an immutable List. This is an easy way to convert a single object into a list.

Can ArrayList contain different object types?

ArrayList. The ArrayList class implements a growable array of objects. ArrayLists cannot hold primitive data types such as int, double, char, and long (they can hold String since String is an object, and wrapper class objects (Double, Integer).

How to cast from a concrete class to an interface type?

But still, it wouldn’t need the full List<> type, it just needs the ICollection<> type (which is also implemented by List<> ), like this: But if the method neededs to get the index of each item, ICollection<> isn’t enough–the method would need an IList<> type.

How to cast generic list types in Java?

But I get this error: CustomerCollection.java:31: incompatible types found : java.util.List required: java.util.List return (List )theList; ^ 1 error So, what’s the correct way to do this cast?

How does casting change the type of an object?

Casting does not change the type of the object. The object always remains the same as when it was created. Casting simply changes the interface through which you are accessing the object. It changes your “view” of the object, if you will. It’s not a problem, though.