Java String lastIndexOf Example
As we disscused in a previous post about Java String indexOf() Example, many times we need to search for a character set in a Java String
. Thus we need a “tool”, a method that will help us make it.
So, in this example we are going to talk about identifying characters and subsequences of characters through Java Strings, with the method lastIndexOf()
.
String static lastIndexOf() method:
The lastIndexOf()
(String or character target) method searches right-to-left inside the given string for a “target” string. The method returns the index number where the target string is last found or -1 if the target is not found. Like equals(), the lastIndexOf()
method is case-sensitive, so uppercase and lowercase chars are considered to be different. The count of the index number starts from left to right though.
int lastIndexOf(String str):
Returns the index within this string of the last occurrence of the specified substring. If it does not occur as a substring, -1 is returned.int lastIndexOf()(String str, int fromIndex):
Returns the index within this string of the last occurrence of the specified character, searching backwards, starting at the specified index. If it does not occur, -1 is returned.
We can use the same methods in order to find the index of the last occurrence of a specified character within the string:
int lastIndexOf(int ch)
int lastIndexOf(int ch, int fromIndex)
Example:
JavaStringLastIndexOf.java
package com.javacodegeeks.javabasics.string; public class JavaStringLastIndexOf { public static void main(String args[]) { String str = new String("Hello JavaCodeGeeks! This is my second post."); String subStr1 = new String("JavaCodeGeeks"); String subStr2 = new String("JavaGeeks"); System.out.print("Found Index :"); System.out.println(str.lastIndexOf('e')); //finds the last occurrence of 'e' System.out.print("Found Index :"); System.out.println(str.lastIndexOf('e', 20)); //finds the last occurrence of 'e' before the 20th character System.out.print("Found Index :"); System.out.println(str.lastIndexOf(subStr1)); //finds the last occurrence of "JavaCodeGeeks" System.out.print("Found Index :"); System.out.println(str.lastIndexOf(subStr1, 15)); //finds the last occurrence of "JavaCodeGeeks" before the 15th character System.out.print("Found Index :"); System.out.println(str.lastIndexOf(subStr2)); //finds the last occurrence of "JavaGeeks" } }
Output:
Found Index :33
Found Index :16
Found Index :6
Found Index :6
Found Index :-1
This was the example of Java String lastIndexOf()
method.