Declarative Objectivity (DO) Language : Tokens : String Tokens
String Tokens
Strings are sequences of characters or bytes.
Syntax 
A string must be enclosed in either single quotation marks or double quotation marks:
RETURN * FROM Customer WHERE lastName == 'Tilson Thomas';
RETURN * FROM Customer WHERE lastName == "Tilson Thomas";
Discussion 
Strings can be stored persistently as attribute values of objects. You can use Literal Expressions to describe and test string values.
 
Escape Sequences for ASCII Characters
You can use escape sequences to represent certain ASCII characters, as shown in the following table:
Escape Sequence
ASCII Character
\0
NUL
\b
Backspace
\n
Newline
\f
Linefeed
\t
Tab
\'
Single quotation mark
\"
Double quotation mark
\\
Backslash
Note:Additional escape sequences are defined for including special characters in a regular expression; see Escape Sequences Within a Regular Expression.
You can include quotes within a single-quoted string using double quotes or escaped single quotes:
'A string with an embedded "quote"'
'A string with an embedded \'quote\''
You can include quotes within a double-quoted string using single quotes or escaped double quotes:
"A string with an embedded 'quote'"
"A string with an embedded \"quote\""
Escape Sequences for Byte Values
You can use escape sequences to construct strings with octal or hex byte values. Each escape sequence specifies a single byte value. A sequence of escape sequences can be used to specify multiple byte values.
Escape Sequence
Byte Values
\octal-digits
Octal byte value. octal-digits are '0'..'7'
\xhex-digits
Hex byte value. hex-digits are
'0'..'9', 'A'..'F', 'a'..'f'
Each of the following specifies a string that contains the byte values 10, 255, 0, 22:
'\12\377\0\31'     // octal
'\xA\xFF\x0\x16'   // hex