Revision history for KeyPgBoolean


Revision [22672]

Last edited on 2019-05-04 17:47:32 by JeffMarshall [Add link to cbool]
Additions:
- ##[[KeyPgCbool|Cbool]]##


Revision [22244]

Edited on 2018-02-17 16:03:56 by badidea [Add link to cbool]
Additions:
Boolean data type. Can hold the values ##[[KeyPgTrue|True]]## or ##[[KeyPgFalse|False]]##
Default value on initialization is ##[[KeyPgFalse|False]]##
Deletions:
Boolean data type. Can hold the values ##[[KeyPgTrue|True]]## or ##[[KeyPgFalse|False]]##.


Revision [21303]

Edited on 2016-04-02 11:23:25 by fxm [Formatting]
Additions:
Output:
Deletions:
**Output:**


Revision [21302]

Edited on 2016-04-02 11:18:00 by fxm [Formatting]
Additions:
**Notes on definition of boolean data type:** //Ideally, the definition of the boolean data type is that it holds the value of ##[[KeyPgTrue|True]]## or ##[[KeyPgFalse|False]]##, and that's it. However, to make this concept a reality, we need a definition that uses real world connections.
A more realistic definition is that the boolean data type is a 1-bit integer, having the value 0 to indicate ##[[KeyPgFalse|False]]## and 1 to indicate ##[[KeyPgTrue|True]]##.
For a practical definition, we must consider, yet again, additional factors. The most significant factor is that the hardware (processor) on which code is executed does not directly support a 1-bit data type; the smallest register or memory size we can work with is 8-bits or 1-byte.
Therefore, a practical definition of boolean data type is an integer, 8 bits wide, having the value 0 or 1, where all other values are undefined. However, because of longstanding differences between C/C""++"" and FB with respect to logical operations, the interpretation of the value must also be considered.
Assume "false" is 0 in both C/C""++"" and FB. C/C""++"" has logical 'not' operator '!' such that '!0' produces '1'.
FB has a bitwise ##[[KeyPgOpNot|Not]]## operator such that 'not 0' produces '-1'. Therefore the definition for a C/C""++"" boolean is an unsigned 1-bit integer, zero extended to fill larger integer types, and the definition for a FB boolean is a signed 1-bit integer, sign extended to fill larger integer types.
However, the purpose and intent of the boolean data type remains, that it should only ever hold a ##[[KeyPgTrue|True]]## value or ##[[KeyPgFalse|False]]## value, regardless of the underlying details.//
Deletions:
**Notes on definition of boolean data type:** //Ideally, the definition of the boolean data type is that it holds the value of ##[[KeyPgTrue|True]]## or ##[[KeyPgFalse|False]]##, and that's it. However, to make this concept a reality, we need a definition that uses real world connections. A more realistic definition is that the boolean data type is a 1-bit integer, having the value 0 to indicate ##[[KeyPgFalse|False]]## and 1 to indicate ##[[KeyPgTrue|True]]##. For a practical definition, we must consider, yet again, additional factors. The most significant factor is that the hardware (processor) on which code is executed does not directly support a 1-bit data type; the smallest register or memory size we can work with is 8-bits or 1-byte. Therefore, a practical definition of boolean data type is an integer, 8 bits wide, having the value 0 or 1, where all other values are undefined. However, because of longstanding differences between C/C""++"" and FB with respect to logical operations, the interpretation of the value must also be considered. Assume "false" is 0 in both C/C""++"" and FB. C/C""++"" has logical 'not' operator '!' such that '!0' produces '1'. FB has a bitwise ##[[KeyPgOpNot|Not]]## operator such that 'not 0' produces '-1'. Therefore the definition for a C/C""++"" boolean is an unsigned 1-bit integer, zero extended to fill larger integer types, and the definition for a FB boolean is a signed 1-bit integer, sign extended to fill larger integer types. However, the purpose and intent of the boolean data type remains, that it should only ever hold a ##[[KeyPgTrue|True]]## value or ##[[KeyPgFalse|False]]## value, regardless of the underlying details.//


Revision [20830]

Edited on 2016-03-12 15:12:31 by fxm [Formatting]
Additions:


Revision [20067]

Edited on 2016-02-10 15:55:03 by DkLwikki [Update link format]
Additions:
[[KeyPgDim|dim]] //variable// [[KeyPgAs|as]] **Boolean**
Boolean data type. Can hold the values ##[[KeyPgTrue|True]]## or ##[[KeyPgFalse|False]]##.
**Notes on definition of boolean data type:** //Ideally, the definition of the boolean data type is that it holds the value of ##[[KeyPgTrue|True]]## or ##[[KeyPgFalse|False]]##, and that's it. However, to make this concept a reality, we need a definition that uses real world connections. A more realistic definition is that the boolean data type is a 1-bit integer, having the value 0 to indicate ##[[KeyPgFalse|False]]## and 1 to indicate ##[[KeyPgTrue|True]]##. For a practical definition, we must consider, yet again, additional factors. The most significant factor is that the hardware (processor) on which code is executed does not directly support a 1-bit data type; the smallest register or memory size we can work with is 8-bits or 1-byte. Therefore, a practical definition of boolean data type is an integer, 8 bits wide, having the value 0 or 1, where all other values are undefined. However, because of longstanding differences between C/C""++"" and FB with respect to logical operations, the interpretation of the value must also be considered. Assume "false" is 0 in both C/C""++"" and FB. C/C""++"" has logical 'not' operator '!' such that '!0' produces '1'. FB has a bitwise ##[[KeyPgOpNot|Not]]## operator such that 'not 0' produces '-1'. Therefore the definition for a C/C""++"" boolean is an unsigned 1-bit integer, zero extended to fill larger integer types, and the definition for a FB boolean is a signed 1-bit integer, sign extended to fill larger integer types. However, the purpose and intent of the boolean data type remains, that it should only ever hold a ##[[KeyPgTrue|True]]## value or ##[[KeyPgFalse|False]]## value, regardless of the underlying details.//
- Not available in the //[[CompilerOptlang|-lang qb]]// dialect unless referenced with the alias ##**""__Boolean""**##.
- ##[[KeyPgTrue|True]]##
- ##[[KeyPgFalse|False]]##
Deletions:
[[KeyPgDim dim]] //variable// [[KeyPgAs as]] **Boolean**
Boolean data type. Can hold the values ##[[KeyPgTrue True]]## or ##[[KeyPgFalse False]]##.
**Notes on definition of boolean data type:** //Ideally, the definition of the boolean data type is that it holds the value of ##[[KeyPgTrue True]]## or ##[[KeyPgFalse False]]##, and that's it. However, to make this concept a reality, we need a definition that uses real world connections. A more realistic definition is that the boolean data type is a 1-bit integer, having the value 0 to indicate ##[[KeyPgFalse False]]## and 1 to indicate ##[[KeyPgTrue True]]##. For a practical definition, we must consider, yet again, additional factors. The most significant factor is that the hardware (processor) on which code is executed does not directly support a 1-bit data type; the smallest register or memory size we can work with is 8-bits or 1-byte. Therefore, a practical definition of boolean data type is an integer, 8 bits wide, having the value 0 or 1, where all other values are undefined. However, because of longstanding differences between C/C""++"" and FB with respect to logical operations, the interpretation of the value must also be considered. Assume "false" is 0 in both C/C""++"" and FB. C/C""++"" has logical 'not' operator '!' such that '!0' produces '1'. FB has a bitwise ##[[KeyPgOpNot Not]]## operator such that 'not 0' produces '-1'. Therefore the definition for a C/C""++"" boolean is an unsigned 1-bit integer, zero extended to fill larger integer types, and the definition for a FB boolean is a signed 1-bit integer, sign extended to fill larger integer types. However, the purpose and intent of the boolean data type remains, that it should only ever hold a ##[[KeyPgTrue True]]## value or ##[[KeyPgFalse False]]## value, regardless of the underlying details.//
- Not available in the //[[CompilerOptlang -lang qb]]// dialect unless referenced with the alias ##**""__Boolean""**##.
- ##[[KeyPgTrue True]]##
- ##[[KeyPgFalse False]]##


Revision [17720]

Edited on 2015-07-19 19:07:33 by JeffMarshall [Added notes on definition of boolean]
Additions:
**Notes on definition of boolean data type:** //Ideally, the definition of the boolean data type is that it holds the value of ##[[KeyPgTrue True]]## or ##[[KeyPgFalse False]]##, and that's it. However, to make this concept a reality, we need a definition that uses real world connections. A more realistic definition is that the boolean data type is a 1-bit integer, having the value 0 to indicate ##[[KeyPgFalse False]]## and 1 to indicate ##[[KeyPgTrue True]]##. For a practical definition, we must consider, yet again, additional factors. The most significant factor is that the hardware (processor) on which code is executed does not directly support a 1-bit data type; the smallest register or memory size we can work with is 8-bits or 1-byte. Therefore, a practical definition of boolean data type is an integer, 8 bits wide, having the value 0 or 1, where all other values are undefined. However, because of longstanding differences between C/C""++"" and FB with respect to logical operations, the interpretation of the value must also be considered. Assume "false" is 0 in both C/C""++"" and FB. C/C""++"" has logical 'not' operator '!' such that '!0' produces '1'. FB has a bitwise ##[[KeyPgOpNot Not]]## operator such that 'not 0' produces '-1'. Therefore the definition for a C/C""++"" boolean is an unsigned 1-bit integer, zero extended to fill larger integer types, and the definition for a FB boolean is a signed 1-bit integer, sign extended to fill larger integer types. However, the purpose and intent of the boolean data type remains, that it should only ever hold a ##[[KeyPgTrue True]]## value or ##[[KeyPgFalse False]]## value, regardless of the underlying details.//


Revision [17719]

The oldest known version of this page was created on 2015-07-16 07:13:08 by CountingPine [Added notes on definition of boolean]
Valid XHTML :: Valid CSS: :: Powered by WikkaWiki



sf.net phatcode