mirror of
https://github.com/QB64-Phoenix-Edition/QB64pe.git
synced 2024-06-29 10:30:36 +00:00
87 lines
4.1 KiB
Plaintext
87 lines
4.1 KiB
Plaintext
{{DISPLAYTITLE:_MEMELEMENT}}
|
|
The [[_MEMELEMENT]] function returns a [[_MEM]] block referring to a variable's memory, but not past it.
|
|
|
|
|
|
{{PageSyntax}}
|
|
: {{Parameter|memoryBlock}} = [[_MEMELEMENT]]({{Parameter|referenceVariable}})
|
|
|
|
|
|
* The {{Parameter|referenceVariable}} parameter designates the existing variable name using the memory block.
|
|
* _MEMELEMENT is the same as [[_MEM]] but in an array it returns the specifications of an element, not the entire array.
|
|
* All values created by memory functions MUST be freed using [[_MEMFREE]] with a valid [[_MEM]] variable type.
|
|
* The _MEMELEMENT type contains the following '''read-only''' elements where ''name'' is the variable name:
|
|
:: ''name'''''.OFFSET''' is the beginning offset of the memory block AS [[_OFFSET]]
|
|
:: ''name'''''.SIZE''' returns the largest available region of memory of the ELEMENT in bytes AS [[_OFFSET]]
|
|
:: ''name'''''.ELEMENTSIZE''' is the [[_BYTE]] size of the elements within the block AS [[_OFFSET]]
|
|
|
|
:::* 2 = [[INTEGER]] values have an element size of 2 bytes
|
|
:::* 4 = [[LONG]] integer and [[SINGLE]] float values have an element size of 4 bytes
|
|
:::* 8 = [[DOUBLE]] float and [[_INTEGER64]] values have an element size of 8 bytes
|
|
:::* 32 = [[_FLOAT]] values have an element size of 32 bytes
|
|
:::* [[LEN]] = [[STRING]] or [[_OFFSET]] byte sizes vary so use [[LEN]](variable) for the number of bytes.
|
|
:: ''name'''''.TYPE''' is the type (represented as bits combined to form a value) AS [[LONG]] (see below).
|
|
|
|
==.TYPE values (version 1.000 and up)==
|
|
:::* 0 = UDT ([[TYPE|user defined type]]) or memory created by [[_MEMNEW]]
|
|
:::* 1 = 1 bit ELEMENT.SIZE=1 *Only used along with specific types (currently integers or floats)
|
|
:::* 2 = 2 bit. ELEMENT.SIZE=2 *
|
|
:::* 4 = 4 bit. ELEMENT.SIZE=4 *
|
|
:::* 8 = 8 bit. ELEMENT.SIZE=8 *
|
|
:::* 16 = 16 bit. ELEMENT.SIZE=16 *
|
|
:::* 32 = 32 bit. ELEMENT.SIZE=32 *
|
|
:::* 64 = 64 bit. ELEMENT.SIZE=64 *
|
|
:::* 128 = 128 bit. ELEMENT.SIZE=128 *
|
|
:::* 256 = 256 bit. ELEMENT.SIZE=256 *
|
|
:::* 512(+ bit*) = integer types only(ie. whole numbers)
|
|
:::* 1024(+ bit*) = floating point types only(ie. numbers that can have a decimal point)
|
|
:::* 2048 = [[STRING]] type only
|
|
:::* 4096(+ 512 + bit*) = [[_UNSIGNED]] integer type only
|
|
:::* 8192 = [[_MEM]] type only
|
|
:::* 16384(+ 512 + bit*)= [[_OFFSET]] type only
|
|
''Note: If a future integer, float or other type doesn't have a size that is 1,2,4,8,16,32,64,128 or 256 it won't have a size-bit set.''
|
|
|
|
===Versions prior to 1.000===
|
|
:::* 1 = Integer types such as [[_BYTE]], [[INTEGER]], [[LONG]], [[_INTEGER64]] or [[_OFFSET]]
|
|
:::* 2 = [[_UNSIGNED]] variable types. Value must be added to the variable type value.(2 cannot be used by itself)
|
|
:::* 3 = ALL [[_UNSIGNED]] [[INTEGER]] type values.(add 1 + 2)
|
|
:::* 4 = Floating point types such as [[SINGLE]], [[DOUBLE]] or [[_FLOAT]]
|
|
:::* 8 = [[STRING]]
|
|
:::* 0 = unknown(eg. created with [[_MEMNEW]]) or [[TYPE|user-defined-types]]
|
|
|
|
<center>'''Note: [[_MEM]] and [[_OFFSET]] values cannot be cast to other variable types.'''</center>
|
|
|
|
|
|
{{PageExamples}}
|
|
''Example:'' Comparing the specifications returned by [[_MEM]] and _MEMELEMENT from an array.
|
|
{{CodeStart}} '' ''
|
|
{{Cl|DIM}} a(1 {{Cl|TO}} 100) {{Cl|AS}} {{Cl|_UNSIGNED}} {{Cl|_BYTE}}
|
|
|
|
{{Cl|DIM}} m1 {{Cl|AS}} {{Cl|_MEM}}
|
|
{{Cl|DIM}} m2 {{Cl|AS}} {{Cl|_MEM}}
|
|
|
|
m1 = {{Cl|_MEM (function)|_MEM}}(a(50)) 'function returns information about array up to specific element
|
|
{{Cl|PRINT}} m1.OFFSET, m1.SIZE, m1.TYPE, m1.ELEMENTSIZE
|
|
|
|
m2 = {{Cl|_MEMELEMENT}}(a(50)) 'function returns information about the specific element
|
|
{{Cl|PRINT}} m2.OFFSET, m2.SIZE, m2.TYPE, m2.ELEMENTSIZE
|
|
|
|
{{Cl|END}} '' ''
|
|
{{CodeEnd}}
|
|
: Output using VERSION .954 ONLY .TYPE values: 1 (integer) + 2 (unsigned)
|
|
{{OutputStart}}28377205 51 3 1
|
|
28377205 1 3 1 {{OutputEnd}}
|
|
: ''Explanation:'' [[_MEM]] returns the info about the array to that element while _MEMELEMENT returns info about that element only.
|
|
::* [[_MEM]] value returns the available array .SIZE as 51 bytes from the designated array element.
|
|
::* [[_MEMELEMENT]] value returns the available element .SIZE as one byte.
|
|
|
|
|
|
{{PageSeeAlso}}
|
|
* [[_MEM]]
|
|
* [[_MEMNEW]]
|
|
* [[_MEMGET]], [[_MEMPUT]]
|
|
* [[_MEMFREE]]
|
|
|
|
|
|
{{PageNavigation}}
|
|
<
|