There are 3 constructors to create an ArrayList. For the
first two construtors, an empty array list is created. The initial capacity is
10 unless it is explicitly specified by using the second constructor. When that
space becomes too small, the list will increase by half of its size.
public ArrayList()
public ArrayList (int initialCapacity)
Note:- Unlike
Vector, you cannot specify a capacity increment. For Sun’s reference
implementation, the formula to increase capacity is
newCapacity=(oldCapacity*3)/2+1. If you happen to call the constructor with a
negative initial capacity, an IllegalArgumentException will be thrown.
Another constructor is copy constructor, creating a new
ArrayList from another collection:
public ArrayList(Collection c)
You can not provide a custom initial capacity .Instead, the
internal array will be sized at 10% larger than the collection size.
One of the easy way of creating ArrayList is
String str[] = {“a”,”b”,”c”,”d”,”e”};
List list=new ArrayList(Arrays.as List(str));
Happy Learning J
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