Literals

Literals serve to write values of any data type.

LITERAL	DESCRIPTION	DECLARATION SYNTAX	EXAMPLE
integer	digits representing integer number	[0-9]+	95623
long integer	digits representing an integer number with absolute value even greater than 2 ³¹, but less than 2 ⁶³	[0-9]+L?	257L, or 9562307813123123L
hexadecimal integer	digits and letters representing an integer number in hexadecimal form	0x[0-9A-F]+	0xA7B0
octal integer	digits representing an integer number in octal form	0[0-7]*	0644
number (double)	a floating point number represented by 64bits in double precision format	.[0-9]	456.123
decimal	digits representing a decimal number	[0-9]+.[0-9]+D	123.456D
double quoted string	string value/literal enclosed in double quotes; escaped characters [\n,\r,\t, \\, ", \b] get translated into corresponding control chars	"…anything except ["]…"	"hello\tworld\n\r"
single quoted string	string value/literal enclosed in single quotes; only one escaped character [\'] gets translated into corresponding char [']	'…anything except [']…'	'hello\tworld\n\r'
list	list of expressions where all elements are of the same data type	[ <element> (, <element>)* ] [] for an empty list	[10, 16 + 1, 31] or ['hello', "world" ]
map	list of key-value mappings where all keys and all values are expressions of the same data type	{ <key> → (, <key> → <value>)* } {} for an empty map	{ "a" → 1, "bb" → 2 }
date	date value	this mask is expected: yyyy-MM-dd	2008-01-01
datetime	datetime value	this mask is expected: yyyy-MM-dd HH:mm:ss	2008-01-01 18:55:00

You cannot use any literal for the byte data type. If you want to write a byte value, you must use any of the conversion functions that return byte and apply it on an argument value.
For information on these conversion functions, see Conversion Functions.

Remember that if you need to assign a decimal value to a decimal field, you should use decimal literal. Otherwise, such number would not be decimal, it would be a double number.
For example:

Decimal value to a decimal field (correct and accurate)

// correct - assign decimal value to decimal field
myRecord.decimalField = 123.56d;

Double value to a decimal field (possibly inaccurate)

// possibly inaccurate - assign double value to decimal field
myRecord.decimalField = 123.56;

The latter might produce inaccurate results.