Programming Gambas from Zip/DataTypes

Data Types and Conversions

Data Types

One byte is the amount of memory required to store a single character such as the letter “A” or the digit “1”. It is eight bits (1’s or 0’s, like little switches that are on or off, up or down). 8 bits = 1 byte. 4 bits = 1 nibble, but that one is not used much.

http://Gambaswiki.org/wiki/lang/type

	Description and Limits	Default value	Size in memory
Boolean	True or false	FALSE	1 byte
Byte	0 to 255	0	1 byte
Short	-32,768 to +32,767	0	2 bytes
Integer	-2,147,483,648 to +2,147,483,647	0	4 bytes
Long	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	0	8 bytes
Single	Single precision	0.0	4 bytes
Float	Floating point or double precision	0.0	8 bytes
Date	Date and time, each stored in an integer.	NULL	8 bytes
String	A variable length string of characters.	NULL	4 bytes on 32 bits systems, 8 bytes on 64 bits systems
Variant	Any datatype.	NULL	12 bytes on 32 bits systems, 16 bytes on 64 bits systems
Object	Anonymous reference to any object.	NULL	4 bytes on 32 bits systems, 8 bytes on 64 bits systems.
Pointer	A memory address.	0	4 bytes on 32 bits systems, 8 bytes on 64 bits systems

Conversions

Some conversions are omitted. Many of these conversions are done automatically as required. For example, these are fine without explicitly having to write the functions:

label1.text = 54.65

Dim d As Date = "09/06/1972 01:45:12"

Dim d As Date = 2484515 gives d the date 05/16/2002

CBool	to a Boolean	An expression is false if it is A false boolean A zero number A zero length string A null date A null object CBool(0) is false CBool(1) is true CBool("Gambas") is true CBool("") is false CBool(Null) is false 0 → False; Anything else → True e.g. 6 is True; -4 is True; 3-(1+2) is False.
CDate	to a Date	CDate("09/06/1972 01:45:12") CDate(2484515)
CFloat or CFlt	to a Float	CFloat("+3.1416") Cfloat("1.0E+3") is 1000
CInt or CInteger	to an Integer	CInt("17") is the number 17 CInt(True) is -1 CInt(Now) is 2490779 CInt(3.2) is 3 CInt(3.9) is 3 CInt(6) is 6 CInt(-7.2) is -7 CInt(-7.9) is -7 TRUE → -1 FALSE → 0
CStr or CString	to a String	CStr(-1972) is -1972 CStr(Now) is 05/16/2002 15:08:31 CStr(Pi) is 3.14159265359
Str	a number or a date into a string	The opposite of Val() Use Format() to have control of what form the number or date takes.
Val	a string into a number or a date	Conversion follows these steps until if finds something it can convert: Look for a date Look for a long Look for an integer Look for a true or false If none, return NULL. IsNull(Val("Gambas")) is True