Or: Difference between revisions

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!align=center| A !! align=center|B !!   A or B  
!align=center| A !! align=center|B !!   A or B  
|-
|-
|   false  ||   false  
|   false  ||   false  
|style="background: #dddddd" |   false
|style="background: #eeeeee" |   false
|-
|-
|   false ||   true  
|   false ||   true  
|style="background: #dddddd" |   true
|style="background: #eeeeee" |   true
|-
|-
|   true ||   false  
|   true ||   false  
|style="background: #dddddd" |   true
|style="background: #eeeeee" |   true
|-
|-
|   true ||   true  
|   true ||   true  
|style="background: #dddddd" |   true
|style="background: #eeeeee" |   true
|}
|}



Revision as of 10:24, 26 October 2007

Boolean operation

Or produces a value of true if some value is true and false if both of its operands are false.

Truth table

A B   A or B  
  false     false     false
  false   true   true
  true   false   true
  true   true   true


Bitwise operation

Bitwise or sets the bit to 1 if one corresponding bits in its operands are 1, and to 0 if they all are 0.

Set a bit

<delphi> function SetBit(const AValue, ABitNumber:integer):integer; begin

  result := AValue or (1 shl ABitNumber);

end; </delphi> If you call SetBit(%1000,1) then get %1010 (%1000 = 8 and %1010 = 10). If you call SetBit(10,2) then get 14 (14 = %1110). If you call SetBit(10,1) then get 10.

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