What will be default type if we don't provide specific type to ArrayList

Answer 1

i think there is no default. You can use everything. This is about 'Generic Classes'

Answer 2

Default type is String..

Example :

import java.util.ArrayList;

public class MyClass {
public static void main(String[ ] args) {

ArrayList <> numbers = new ArrayList <>();

numbers .add(2);
numbers .add(3);

System.out.println(numbers.get(0)); // accepted cause only printing // output : 2

System.out.println((numbers.get(0))+ 4); // not accepted unless array defined as Integer because of the add +

}
}