Java Summary - Building Java Programs: A Back to Basics Approach - page 1111

Useful Methods of ArrayList Objects

Method Description ArrayList<String> example

Adds the given value at the
end of the list

add(value) list.add("end");

Adds the given value at the
given index, shifting
subsequent values right

add(index, value) list.add(1, "middle");

Removes all elements from
the list

clear() list.clear();

Returns true if the given
value appears in the list

contains(value) list.contains("hello")

Gets the value at the given
index

get(index) list.get(1)

Returns the index of the first
occurrence of the given value
in the list ( -1 if not found)

indexOf(value) list.indexOf("world")

Returns the index of the last
occurrence of the given value
in the list ( -1 if not found)

lastIndexOf(value) list.lastIndexOf("hello")

Removes the value at the
given index, shifting subse-
quent values left

remove(index) list.remove(1);

Replaces the given value at
the given index with the
given value

set(index, value) list.set(2, "hello");

Returns the current number
of elements in the list

size() list.size()