The trimToSize() method of StringBuffer class is the inbuilt method used to trims the capacity used for the character sequence of StringBuffer object. If the buffer used by StringBuffer object is larger than necessary to hold its current sequence of characters, then this method is called to resize the StringBuffer object for converting this object to more space efficient. Calling this method may, but is not required to, affect the value returned by a subsequent call to the capacity() method.
Syntax:
public void trimToSize()
Returns: This method does not return anything.
Below programs illustrate the StringBuffer.trimToSize() method:
Example 1:
// Java program to demonstrate// the trimToSize() Method.  class GFG {    public static void main(String[] args)    {          // create a StringBuffer object        // with a String pass as parameter        StringBuffer str            = new StringBuffer("GeeksForGeeks");          // add more string to StringBuffer        str.append("Contribute");          // print capacity        System.out.println("Capacity before "                           + "applying trimToSize() = "                           + str.capacity());          // applying trimToSize() Method        str.trimToSize();          // print string        System.out.println("String = " + str.toString());          // print capacity        System.out.println("Capacity after"                           + " applying trimToSize() = "                           + str.capacity());    }} |
Output:
Capacity before applying trimToSize() = 29 String = GeeksForGeeksContribute Capacity after applying trimToSize() = 23
Example 2:
// Java program to demonstrate// the trimToSize() Method.  class GFG {    public static void main(String[] args)    {          // create a StringBuffer object        // with a String pass as parameter        StringBuffer str            = new StringBuffer();          // add more string to StringBuffer        str.append("GeeksForGeeks classes");          // print capacity        System.out.println("Capacity before"                           + " applying trimToSize() = "                           + str.capacity());          // applying trimToSize() Method        str.trimToSize();          // print string        System.out.println("String = " + str.toString());          // print capacity        System.out.println("Capacity after "                           + "applying trimToSize() = "                           + str.capacity());    }} |
Output:
Capacity before applying trimToSize() = 34 String = GeeksForGeeks classes Capacity after applying trimToSize() = 21
References:
https://docs.oracle.com/javase/10/docs/api/java/lang/StringBuffer.html#trimToSize()
