The Java® Language Specification, Java SE 7 Edition, Fourth Edition

10.9. An Array of Characters is Not a String

In the Java programming language, unlike C, an array of char is not a String, and neither a String nor an array of char is terminated by ‘\u0000’ (the NUL character).

A String object is immutable, that is, its contents never change, while an array of char has mutable elements.

The method toCharArray in class String returns an array of characters containing the same character sequence as a String. The class StringBuffer implements useful methods on mutable arrays of characters.