What is the difference between append and write methods of java.io.writer?

java writer
Svish picture Svish · May 10, 2011 · Viewed 31.8k times · Source

The java.io.Writer interface has two methods called append and write. What are the differences between these two? It even says that

An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation out.write(c)

so what is the reason for having two method name variants?

Answer

Peter Lawrey picture Peter Lawrey · May 10, 2011

There are minor differences between append() and write(). All of which you can work out by reading the Javadocs. Hint. ;)

  • write will only take a String which must not be null and returns void
  • append will take any CharSequence which can be null and return the Writer so it can be chained.

write is an older style format created before CharSequence was available.

These methods are overloaded so that there is a

  • write(int) where the int is cast to a char. append(char) must be a char type.
  • write(char[] chars) takes an array of char, there is no equivalent append().

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