Push_back and pop_back in java

I am coming from a C++ background. I use vector push_back and pop_back methods to push and pop out elements from the vector. I know arraylist is sort of equivalent to vector, but I don'f find equivalent methods to push_back and pop_back in arraylist API. The closet I could find is LinkedList. Am I missing something or is there any other equivalent to vector in C++?

Any help is appreciated.

4 Answers

Use add() from ArrayList to push_back.

For pop_back you have to play around a bit more with indexes and remove().

Let's look at this example:

// push_back equivalent ArrayList<int> a = new ArrayList<int>(); a.add(2); // Add element to the ArrayList. a.add(4); // pop_back equivalent. a.remove(a.size()-1); // Remove the last element from the ArrayList. 

Use ArrayList for dynamically add and remove element.

For push_back() use .add()

add() method to add elements in the list

List<Integer> arrlist = new ArrayList<Integer>(); arrlist.add(10); 

For pop_back() use .remove()

remove() used for removing the element at the specified position in this list. So, pass last index in method to delete last element

arrlist.remove(arrlist.size() - 1); 

You can use add() for push_back() and remove() for pop_back().

ArrayList<data_type> data = new ArrayList<data_type>(); data.add(value1); data.add(value2); data.remove(data.size() - 1); 

P.S : arraylist is a container not API.

We can use the LinkedList<E> data structure

Adding at the end by: add(E e)

removing at the end by using: pollLast()

Example:

package test; import java.util.*; public class test{ public static void main(String args[]){ LinkedList<String> al=new LinkedList<String>(); al.add("element1"); al.add("element2"); al.add("element3"); Iterator<String> itr=al.iterator(); while(itr.hasNext()){ System.out.print(itr.next()+" "); } System.out.println(" "); al.add("element4"); itr=al.iterator(); while(itr.hasNext()){ System.out.print(itr.next()+ " "); } System.out.println(" "); //pop_back al.pollLast(); itr=al.iterator(); while(itr.hasNext()){ System.out.print(itr.next()+" "); } } } 

result:

element1 element2 element3 element1 element2 element3 element4 element1 element2 element3