Java - StringWriter append(CharSequence csq,int start,int end) method

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Description

The Java StringWriter append(CharSequence csq,int start,int end) method appends a subsequence of the specified character sequence to this writer.

Declaration

Following is the declaration for java.io.StringWriter.append(CharSequence csq,int start,int end) method.

public StringWriter append(CharSequence csq,int start,int end)

Parameters

• csq − The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.

• start − The index of the first character in the subsequence.

• end − The index of the character following the last character in the subsequence.

Return Value

This method returns this writer.

Exception

IndexOutOfBoundsException − If start or end are negative, start is greater than end, or end is greater than csq.length().

Example - Usage of StringWriter append(CharSequence csq,int start,int end) method

The following example shows the usage of StringWriter append(CharSequence csq,int start,int end) method.

StringWriterDemo.java

package com.tutorialspoint;

import java.io.StringWriter;

public class StringWriterDemo {
   public static void main(String[] args) {

      // create a new writer
      StringWriter sw = new StringWriter();

      // create a new sequence
      CharSequence sq = "Hello World";

      // append sequence
      sw.append(sq, 0, 5);

      // print result     
      System.out.println("" + sw.toString());

      // append second sequence
      sw.append(sq, 5, 5);

      // print result again
      System.out.println("" + sw.toString());
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Hello
Hello

Example - Appending a Substring from a String

The following example shows the usage of StringWriter append(CharSequence csq,int start,int end) method.

StringWriterDemo.java

package com.tutorialspoint;

import java.io.StringWriter;

public class StringWriterDemo {
   public static void main(String[] args) throws Exception {
      StringWriter sw = new StringWriter();
      String text = "HelloWorld";

      sw.append(text, 0, 5);  // "Hello"
      sw.append(" ");         
      sw.append(text, 5, 10); // "World"

      System.out.println("Output: " + sw.toString());
   }
}

Output

Let us compile and run the above program, this will produce the following result−

Output: Hello World

Explanation

• Appends "Hello" from index 0 to 5.

• Appends "World" from index 5 to 10.

Example - Appending a Portion of StringBuilder

The following example shows the usage of StringWriter append(CharSequence csq,int start,int end) method.

StringWriterDemo.java

package com.tutorialspoint;

import java.io.StringWriter;

public class StringWriterDemo {
   public static void main(String[] args) {
      StringWriter sw = new StringWriter();
      StringBuilder sb = new StringBuilder("FunctionalInterfaces");

      sw.append(sb, 0, 10);  // "Functional"
      sw.append(" ");
      sw.append(sb, 10, sb.length());  // "Interfaces"

      System.out.println("Output: " + sw.toString());
   }
}

Output

Let us compile and run the above program, this will produce the following result−

Output: Functional Interfaces

Explanation

• StringBuilder content is split using indices.

• Appends "Functional" (0 to 10) and "Interfaces" (10 to end).