AbstractList lastIndexOf() method in Java with Examples
Last Updated :
21 Nov, 2019
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The lastIndexOf() method of java.util.AbstractList class is used to return the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the highest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.
Syntax:
Java
Java
public int lastIndexOf(Object o)Parameters: This method takes Object o as a parameter which is the element to search for. Returns Value: This method returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element. Exception: This method throws NullPointerException if the specified element is null and this list does not permit null elements. Below are the examples to illustrate the lastIndexOf() method. Example 1:
// Java program to demonstrate
// lastIndexOf() method
// for String value
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
// Creating object of AbstractList<String>
AbstractList<String>
arrlist1 = new ArrayList<String>();
// Populating arrlist1
arrlist1.add("A");
arrlist1.add("B");
arrlist1.add("A");
arrlist1.add("B");
arrlist1.add("E");
// print arrlist1
System.out.println("ArrayList : "
+ arrlist1);
// getting the index of last occurrence
// using lastIndexOf() method
int lastindex = arrlist1.lastIndexOf("A");
// printing the Index
System.out.println("Last index of A : "
+ lastindex);
}
catch (NullPointerException e) {
System.out.println("Exception thrown : " + e);
}
}
}
Output:
Example 2:
ArrayList : [A, B, A, B, E] Last index of A : 2
// Java program to demonstrate
// lastIndexOf() method
// for NullPointerException
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
// Creating object of AbstractList<String>
AbstractList<String> arrlist1 = null;
// print arrlist1
System.out.println("ArrayList : "
+ arrlist1);
// getting the index of last occurrence
// using lastIndexOf() method
System.out.println("\nTrying to get"
+ " the index from"
+ " null ArrayList");
int lastindex = arrlist1.lastIndexOf("B");
// printing the Index
System.out.println("Last index of B : "
+ lastindex);
}
catch (NullPointerException e) {
System.out.println("Exception thrown : " + e);
}
}
}
Output:
ArrayList : null Trying to get the index from null ArrayList Exception thrown : java.lang.NullPointerException
