mirror of
https://github.com/QB64Official/qb64.git
synced 2024-08-22 03:15:07 +00:00
57 lines
1.7 KiB
Text
57 lines
1.7 KiB
Text
{{DISPLAYTITLE:_READBIT}}
|
|
The [[_READBIT]] function is used to check the state of a specified bit of a integer value.
|
|
|
|
|
|
{{PageSyntax}}
|
|
:{{Parameter|result}} = [[_READBIT]]({{Parameter|numericalVariable}}, {{Parameter|numericalValue}})
|
|
|
|
|
|
{{PageParameters}}
|
|
* {{Parameter|numericalVariable}} is the variable to read the state of a bit of and can be of the following types: [[_BYTE]], [[INTEGER]], [[LONG]], or [[_INTEGER64]].
|
|
* Integer values can be signed or [[_UNSIGNED]].
|
|
* {{Parameter|numericalValue}} the number of the bit to be read.
|
|
|
|
|
|
{{PageDescription}}
|
|
* Used to check the current state of a bit in an integer value.
|
|
* Returns -1 if the bit is set(1), otherwise returns 0 if the bit is not set(0)
|
|
* Bits start at 0 (so a [[_BYTE]] has bits 0 to 7, [[INTEGER]] 0 to 15, and so on)
|
|
|
|
{{PageAvailability}}
|
|
* Version 1.4 and up.
|
|
|
|
|
|
{{PageExamples}}
|
|
''Example 1:''
|
|
{{CodeStart}}
|
|
A~%% = {{Cl|_SETBIT}}(A~%%,4)
|
|
{{Cl|PRINT}} "Bit 4 is currently ";
|
|
IF {{Cl|_READBIT}}(A~%%,4) = -1 THEN {{Cl|PRINT}} "ON" ELSE {{Cl|PRINT}} "OFF"
|
|
{{Cl|PRINT}} "And bit 2 is currently ";
|
|
IF {{Cl|_READBIT}}(A~%%,2) = -1 THEN {{Cl|PRINT}} "ON" ELSE {{Cl|PRINT}} "OFF"
|
|
{{CodeEnd}}
|
|
{{OutputStart}}
|
|
Bit 4 is currently ON
|
|
And bit 2 is currently OFF
|
|
{{OutputEnd}}
|
|
|
|
''Example 2:''
|
|
{{CodeStart}}
|
|
B& = 12589575
|
|
{{Cl|PRINT}} "B& ="; B&
|
|
FOR I%% = 31 TO 0 STEP -1 '32 bits for a {{Cl|LONG}} value
|
|
Binary$ = Binary$ + {{Cl|LTRIM$}}({{Cl|STR$}}({{Cl|ABS}}({{Cl|_READBIT}}(B&, I%%))))
|
|
NEXT I%%
|
|
{{Cl|PRINT}} "B& in binary is: "; Binary${{CodeEnd}}
|
|
{{OutputStart}}
|
|
B& = 12589575
|
|
B& in binary is: 00000000110000000001101000000111
|
|
{{OutputEnd}}
|
|
|
|
|
|
{{PageSeeAlso}}
|
|
* [[_SHL]], [[_SHR]], [[INTEGER]], [[LONG]]
|
|
* [[_SETBIT]], [[_BYTE]], [[_INTEGER64]]
|
|
* [[_RESETBIT]], [[_TOGGLEBIT]]
|
|
|
|
{{PageNavigation}}
|