Unicode escape sequence
Reason: In Java, Unicode characters can be used in string literals, comments, and commands, and are expressed by Unicode Escape Sequences. A Unicode escape sequence is made up of the following articles:
- A backslash '\' (ASCII character 92)
- A 'u' (ASCII 117)
- One or more additional 'u' characters that are optional.
- A four hexadecimal digits (a character from 0 - 9 or a-f or A-F)