Find first and last element of ArrayList in java
Prerequisite: ArrayList in Java
Given an ArrayList, the task is to get the first and last element of the ArrayList in Java,
Examples:
Input: ArrayList = [1, 2, 3, 4] Output: First = 1, Last = 4 Input: ArrayList = [12, 23, 34, 45, 57, 67, 89] Output: First = 12, Last = 89
Approach:
- Get the ArrayList with elements.
- Get the first element of ArrayList with use of get(index) method by passing index = 0.
- Get the last element of ArrayList with use of get(index) method by passing index = size – 1.
Below is the implementation of the above approach:
// Java code to find first and last element // of ArrayList import java.util.ArrayList; public class GFG { // main method public static void main(String[] args) { // creating an Empty Integer ArrayList ArrayList<Integer> list = new ArrayList<Integer>( 5 ); // using add() to initialize values list.add( 1 ); list.add( 2 ); list.add( 3 ); list.add( 4 ); // printing initial value ArrayList System.out.print( "ArrayList: " + list); // find first element int first = list.get( 0 ); // find last element int last = list.get(list.size() - 1 ); // print first and last element of ArrayList System.out.println( "\nFirst : " + first + ", Last : " + last); } } |
Output:
ArrayList: [1, 2, 3, 4] First : 1, Last : 4
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