Java uses the escape sequences listed in Table 13.2 to represent certain special character values. These escape sequences may appear in any Java char or String literal.
|Escape Sequence||Character Value|
The character corresponding to the octal value xxx, where xxx is between 000 and 0377.
The Unicode character with encoding xxxx, where xxxx is one to four hexidecimal digits. Unicode escapes are distinct from the other escape types listed here; they are described below in more detail.
Java characters, strings, and identifiers (e.g., field, method, and class names) are composed of 16-bit Unicode characters. The Unicode \u escape sequence may be used anywhere in a Java program (not only in char and String literals) to represent a Unicode character.
Unicode \u escape sequences are processed before the other escape sequences described in Character Escape Sequences, and thus the two types of escape sequences can have very different semantics. A Unicode escape is simply an alternative way to represent a character which may not be displayable on non-Unicode systems. The character escapes, however, can represent special characters in a way that prevents the usual interpretation of those characters by the compiler.