StringBuffer delete() Method in Java with Examples

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The java.lang.StringBuffer.delete() is an inbuilt method in Java which is used to remove or delete the characters in a substring of this sequence. The substring starts at a specified index start_point and extends to the character at the index end_point.

Syntax :

public StringBuffer delete(int start_point, int end_point)

Parameters : The method accepts two parameters of integer type:
start_point – This refers to the beginning index and is included in the count.
end_point – This refer to the ending index and is excluded from the count.

Return Value : The method returns the string after deleting the substring formed by the range mentioned in the parameters.

Exceptions : StringIndexOutOfBoundsException occurs if the start_point is negative, greater than length(), or greater than the end_point.

Examples :

Input: String = "Apple"
            start_point = 2 
            end_point = 4

Output: Ape

Input: String = "Lazyroar"
       start_point = 2 
       end_point = 7

Output: GerGeeks

Below programs illustrate the java.lang.StringBuffer.delete() method:
Program 1:

java

// Java program to illustrate the
// java.lang.StringBuffer.delete()
import java.lang.*;
  
public class geeks {
  
    public static void main(String[] args)
    {
  
        StringBuffer sbf = new StringBuffer("Geeksforgeeks");
        System.out.println("string buffer = " + sbf);
  
        // Deleting characters from index 2 to 7
        sbf.delete(6, 8);
        System.out.println("After deletion string buffer is = " + sbf);
    }
}

Output:

string buffer = Geeksforgeeks
After deletion string buffer is = Geeksfgeeks

Program 2:

java

// Java program to illustrate the
// java.lang.StringBuffer.delete()
import java.lang.*;
  
public class geeks {
  
    public static void main(String[] args)
    {
  
        StringBuffer sbf = new StringBuffer("Welcome to Geeksforgeeks");
        System.out.println("string buffer = " + sbf);
  
        // deleting characters from index 5 to index 9
        sbf.delete(5, 9);
        System.out.println("After deletion string buffer is = " + sbf);
    }
}

Output:

string buffer = Welcome to Geeksforgeeks
After deletion string buffer is = Welcoo Geeksforgeeks

Program 3: Here the index is negative.

java

// Java program to illustrate the
// java.lang.StringBuffer.delete()
import java.lang.*;
  
public class geeks {
  
    public static void main(String[] args)
    {
  
        StringBuffer sbf = new StringBuffer("Welcome to Geeksforgeeks");
        System.out.println("string buffer = " + sbf);
  
        sbf.delete(-5, 9);
        System.out.println("After deletion string buffer is = " + sbf);
    }
}

Output:

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: 
                                         String index out of range: -5
    at java.lang.AbstractStringBuilder.delete(AbstractStringBuilder.java:756)
    at java.lang.StringBuffer.delete(StringBuffer.java:430)
    at geeks.main(geeks.java:13)

Program 4: Here the index is not present.

java

// Java program to illustrate the
// java.lang.StringBuffer.delete()
import java.lang.*;
  
public class geeks {
  
    public static void main(String[] args)
    {
  
        StringBuffer sbf = new StringBuffer("Welcome to Geeksforgeeks");
        System.out.println("string buffer = " + sbf);
  
        sbf.delete(99, 109);
        System.out.println("After deletion string buffer is = " + sbf);
    }
}

Output:

Exception in thread "main" java.lang.StringIndexOutOfBoundsException
    at java.lang.AbstractStringBuilder.delete(AbstractStringBuilder.java:760)
    at java.lang.StringBuffer.delete(StringBuffer.java:430)
    at geeks.main(geeks.java:13)