error while using Collection class

[stmfc]

what is wrong with the code below:

import java.util.*;
public class Class1 {
 
    public static void main(String[] args) {
 
        Collection c;
        c.add("aaa");
        c.add("bbb");
        c.add("ccc");
 
    }
 
}
 

i got this error:

java.lang.Error: Unresolved compilation problems:
The local variable c may not have been initialized
The local variable c may not have been initialized
The local variable c may not have been initialized

[JosAH]

Guess what: the compiler is going to tell you that you didn't initialize a local
variable. Have a look whether or not you have initialized local variable 'c'.

kind regards,

Jos

[stmfc]

using add method i think i am initializing the local variable c,
i am new to java, in C++ vector classes are initialized in this way.
if this is not true in java, tell me how can i initialize c,and add values to store in variable c

[JosAH]

using add method i think i am initializing the local variable c,
i am new to java, in C++ vector classes are initialized in this way.
if this is not true in java, tell me how can i initialize c,and add values to store in variable c

Think of those Java object variables as pointers (or 'references' as they are called
in Java) to the actual objects. The pointer/reference 'c' doesn't point to an actual
object yet, i.e. it isn't initialized. You have to do something like this:

Collection c= new ArrayList<String>();
 

Now 'c' points to an ArrayList that can store strings (similar to vector<string> in
C++). Also in C++ it isn't true that an 'add' method initializes the container.

kind regards,

Jos