In this tutorial, we will discuss the Java StringBuilder lastIndexOf() method with the help of example programs.
The syntax of lastIndexOf() method is:
//Returns the index of last occurrence of string "welcome"
sb.lastIndexOf("welcome");
//Returns index of last occurrence of "welcome" before index 5
sb.lastIndexOf("welcome", 5);
Here, sb is an object of StringBuilder class.
lastIndexOf() Description
There are two variations of lastIndexOf() method in Java StringBuilder class.
public int lastIndexOf(String str): It returns the index of last occurrence of the string str in the StringBuilder instance.
public int lastIndexOf(String str, int fromIndex): It returns the index of last occurrence of specified string before the fromIndex.
To get index of first occurrence of specified string use Java StringBuilder indexOf() method.
lastIndexOf() Parameters
The lastIndexOf() method of Java StringBuilder class takes a single parameter:
- str: The String str represents the character sequence that needs to be searched in the StringBuilder instance
sb. - fromIndex: It represents an index. The search of the string str ends here.
lastIndexOf() Return Value
- It returns an integer value that represents the index of the last occurrence of specified string str. If the specified string is not found then this method returns -1.
Example 1: Search string without fromIndex
public class JavaExample {
public static void main(String[] args) {
StringBuilder sb = new StringBuilder("Text1Text2");
System.out.println("String: " + sb);
// last occurrence of string "Text"
System.out.println("Last Occurrence of String 'Text': "+
sb.lastIndexOf("Text"));
}
}
Output:
Example 2: Search string before an index
public class JavaExample {
public static void main(String[] args) {
StringBuilder sb = new StringBuilder("BatRat");
System.out.println("String: " + sb);
// last occurrence of string "at" before 3
System.out.println("Last Occurrence of 'at' before index 3: "+
sb.lastIndexOf("at", 3));
}
}
Output:
Example 3: When specified string is not found
public class JavaExample {
public static void main(String[] args) {
StringBuilder sb = new StringBuilder("BatRat");
System.out.println("String: " + sb);
// last occurrence of string "Pet"
System.out.println("Last Occurrence of 'Pet': "+
sb.lastIndexOf("Pet"));
}
}
Output:
Example 4: When string not found within specified Index
public class JavaExample {
public static void main(String[] args) {
StringBuilder sb = new StringBuilder("BatRat");
System.out.println("String: " + sb);
// last occurrence of string "at" before 0
System.out.println("Last Occurrence of 'at' before index 0: "+
sb.lastIndexOf("at", 0));
}
}
Output:
