How to Use Java String Class lastIndexOf() Method

Function Description

Java String class lastIndexOf() method is used to get the index value of the last occurrence of the specified character within the string. It does backward search and backward search starts from the last index value or we can say at last character of the string. If fromIndex value is given, the backward search starts from the given fromIndex value. Value -1 is returned, if it does not find the specified character/sequence of characters within the String.

 In java lastIndexOf  method is defined as overloaded method

  1. Method to get the index value of the last occurrence of the specified character within the string. Backward search starts from the last character of the string.

  2. Method to get the index value of the last occurrence of the specified character within the string. The backward search for the specified character starts from the specified index.

  3. Method to get the index value of the last occurrence of the specified sequence of characters(string) within the string. Backward search starts from the last character of the string.

  4. Method to get the index value of the last occurrence of the specified sequence of characters(string) within the string, Specified string search starts from the specified index. The backward search for the specified string starts from the specified index.

Method Signature

Method to get the index value of last occurrence of the specified character

public int lastIndexOf(int ch)

Method to get the index value of the last occurrence of the specified character, the search starts at given fromIndex.

public int lastIndexOf (int ch, int fromIndex)

Method to get the index value of last occurrence of the specified string

public int lastIndexOf (String str)

Method to get the index value of the last occurrence of the specified string, searches start from given fromIndex

public int lastIndexOf (String str, int fromIndex)

Parameter(s)

ch: Character for which the last occurrence of character index value to be searched.

fromIndex: Index value from where the backward search for character/string will start. If fromIndex value is more than the length of the string, the search will be in the entire string, if fromIndex value is 0 or less than 0, the returned value will be -1.

str:. Sequence of characters(string) for which the last occurrence of index value to be searched.

Return Type

Index value of the last occurrence of character/sequence of characters within the string in int datatype. It returns -1, if the specified character/sequence of characters is not found within the string.

Examples of Java String Class IndexOf() Method:

Method to get the index value of the last occurrence of the specified character

public class ExampleStringLastIndex {
 
    private void getLastIndexOfCharacter() {

          String str = new String("Welcome to String class indexOf() function learning");

          // returns last index of W character

          int index = str.lastIndexOf('W');

          System.out.println("Index value of W character : " + index);
 
          // returns last index f character

          index = str.lastIndexOf('f');

          System.out.println("Index value of F character : " + index);
 
          // return last index k character

          index = str.lastIndexOf('k');

          System.out.println("Index value of K character : " + 
index);

    }
 
    public static void main(String[] args) {

          ExampleStringLastIndex example = new ExampleStringLastIndex();

          example.getLastIndexOfCharacter();
    }
 
}


Output:

Index value of W character : 0

Index value of F character : 34

Index value of K character : -1

Method to get the index value of the last occurrence of the specified character, searches start from given fromIndex

public int lastIndexOf (int ch, int fromIndex)

package com.java.test;
 
public class ExampleStringLastIndex {
 
    private void getLastIndexOfCharacterFromSpecifiedIndex() {

          String str = new String("Welcome to String class indexOf() function learning");

          // returns last index of W character

          int index = str.lastIndexOf('W', 10);

          System.out.println("Index value of W character : " + index);
 
          // returns last index f character

          index = str.lastIndexOf('f', 45);

          System.out.println("Index value of F character : " + index);
 
          // return last index f character

          index = str.lastIndexOf('c', 70);

          System.out.println("Index value of c character : " + index);
 
          // return last index f character

          index = str.lastIndexOf('f', 0);

          System.out.println("Index value of f character : " + index);
 
          // return last index f character

          index = str.lastIndexOf('f', -7);

          System.out.println("Index value of f character : " + index);
    }
 
    public static void main(String[] args) {

          ExampleStringLastIndex example = new ExampleStringLastIndex();

          example.getLastIndexOfCharacterFromSpecifiedIndex();

    }
 
}


Output:

Index value of W character : 0

Index value of F character : 34

Index value of c character : 37

Index value of f character : -1

Index value of f character : -1

Method to get the index value of the last occurrence of the specified string

package com.java.test;
 
public class ExampleStringLastIndex {
 
    private void getLastIndexOfString() {

          String str = new String("Welcome to String class indexOf() function learning");

          // returns last index of index string

          int index = str.lastIndexOf("index", 45);

          System.out.println("Index value of index : " + index);
 
          // returns last index of CLASS string

          index = str.lastIndexOf("CLASS", 45);

          System.out.println("Index value of CLASS : " + index);
    }
 
    public static void main(String[] args) {

          ExampleStringLastIndex example = new ExampleStringLastIndex();

          example.getLastIndexOfString();
    }
 
}


OutPut:

Index value of index : 24

Index value of CLASS : -1

Method to get the index value of the last occurrence of the specified string, searches start from given fromIndex

package com.java.test;
 
public class ExampleStringLastIndex {
 
    private void getLastIndexOfString() {

          String str = new String("Welcome to String class indexOf() function learning");

          // returns last index of Welcome string

          int index = str.lastIndexOf("Welcome", 10);

          System.out.println("Index value of Welcome string : " + index );
 
          // returns last index of function string

          index = str.lastIndexOf("function", 49);

          System.out.println("Index value of function string : " + index);
 
          // return last index of class string

          index = str.lastIndexOf("class", 70);

          System.out.println("Index value of class string : " + index);
 
          // return last index of function string

          index = str.lastIndexOf("fucntion", 0);

          System.out.println("Index value of function string : " + index);
 
          // return last index function character

          index = str.lastIndexOf("fucntion", -7);

          System.out.println("Index value of function string : " + index);
    }
 
    public static void main(String[] args) {

          ExampleStringLastIndex example = new ExampleStringLastIndex();

          example.getLastIndexOfString();

    }
 
}
 

Output:

Index value of Welcome string : 0

Index value of function string : 34

Index value of class string : 18

Index value of function string : -1

Index value of function string : -1

Other Methods of String Class

SequenceMethodDescription
1char charAt(int index)This method is used to return the character of the string at specified index. First character is at index 0 while last is at string length-1 . StringIndexOutOfBounds Exception is thrown if valid index value is not passed.
2int length()Returns the number of characters count  in  a string.
3static String format(String format, Object… args)Return the formatted String. It is a static method and formats the string as per passing format and argument(s).
4static String format(Locale l, String format, Object… args)Return the formatted String. It is a static method and formats the string as per passing format and argument(s) and locale.
5String substring(int beginIndex)Returns substring from the given index position to the end index of the string.
6String substring(int beginIndex, int endIndex)Returns substring from the specified begin index to the specified end index.
7boolean contains(CharSequence s)Returns boolean value(true/false). It searches the given sequence of characters within the string and returns true/false accordingly. Characters will be case sensitive while searching in string.
8static String join(CharSequence delimiter, CharSequence… elements)Returns joined string. This method joins each passing String using the specified delimiter. It is a static method.
9static String join(CharSequence delimiter, Iterable<? extends CharSequence> elements)Returns the joined string. This method joins each passing string object of an iterate object using the specified delimiter and returns the concatenated string. It is a static method.
10boolean equals(Object another)Returns boolean value(true/false). It checks the equality of string with the passing object.
11boolean isEmpty()Returns boolean value(true/false). It returns true if the string is empty otherwise returns false.
12String concat(String str)Returns the concatenating string. It concatenates the passing string at the end of the string.
13String replace(char old, char new)Return the replaced string. It replaces all occurrences of the specified character with the new character.
14String replace(CharSequence old, CharSequence new)Return the replaced string. It replaces all occurrences of the specified Character sequence with the specified new Character sequence.
15String replaceAll(String regex, String replacement)Returns the replaced string. It replaces all occurrences of the sequence of characters with the given replacement string that are matching with the given regular expression.
16String replaceFirst(String regex, String replacement)Returns the replaced string. It replaces the first matching sequence of characters with the replacement string that matches with the given regular expression.
17static boolean equalsIgnoreCase(String another)Returns the boolean (true/false) value. It compares the passing string with string by ignoring the case. It  compares the content irrespective of lowercase or uppercase of the character(s).
18String[] split(String regex)Returns the array of strings resulting from splitting of the string     around matches of the given regular expression. String is breaked into strings from all  the matching regular expressions.
19String[] split(String regex, int limit)Returns the array of strings resulting from splitting of the string     around matches of the given regular expression. It breaks the string from all the matching regular expression upto the given limit.
20String intern()Returns an interned string. This method helps to compare two objects using == operator and checks in a string constant pool. it is faster for comparison.
21int indexOf(int ch)Returns the index value of first occurrence of the specified character within the string
22int indexOf(int ch, int fromIndex)Returns the index value of first occurrence of the specified character from the substring starting from specified index
23int indexOf(String substring)Returns the index value of first occurrence of the specified substring within the string.
24int indexOf(String substring, int fromIndex)Returns the index value of the first occurrence of the specified string within the substring starting from specified index to end of the string index.
25String toLowerCase()Returns all the characters of the string in lowercase .
26String toLowerCase(Locale l)Returns all the characters of the string in lowercase using specified locale.
27String toUpperCase()Returns all the characters of the string in uppercase.
28String toUpperCase(Locale l)Returns all the characters of the string in uppercase using specified locale.
29String trim()Returns the string after removing the white space from the beginning and end of the string.
30static String valueOf(int value)Return the converted string. It converts the objects and all primitive types of values into string. It is a static method.

In this article, we learned all about the lastIndexOf() method of String class with examples. Apart from the lastIndexOf() method we got an idea about other String methods too. We will come up with more articles explaining other String methods with examples. For more details please click on the respective methods link.

This article was written by Renu Singh

14+ Years of experience in various phases of the software development life cycle. Specialties: Java/J2EE, Struts, Hibernate, JSF, JSP, Servlets, AJAX, Oracle, Oracle Knowledge, SQL Server 2000, DB2, EJB3.0. Companies Worked For: 1) Tata Consultancy Services 2) Infogain 3) TS Infotech 4) Daffodil Software Ltd.

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