question mark inside C# syntax [duplicate]

Answer 1

if ( diff >= differenceThreshold ) || ( diff <= differenceThresholdNeg ) ) 
*currFrame = (byte) 255;
else *currFrame =  (byte) 0;

Answer 2

'?:' is a conditional operator, you can read about it here: http://msdn.microsoft.com/en-us/library/ty67wk28(v=vs.80).aspx

Answer 3

The conditional operator (?:) returns one of two values depending on the value of a Boolean expression. Following is the syntax for the conditional operator.

condition ? first_expression : second_expression;

C# reference: http://msdn.microsoft.com/en-us/library/ty67wk28.aspx

In your case currFrame will be assigned a value of 255 if ( diff >= differenceThreshold ) || ( diff <= differenceThresholdNeg ) is true, otherwise value 0 will be assigned.

Answer 4

this is the same as

if(( diff >= differenceThreshold ) || ( diff <= differenceThresholdNeg ) )
     currFrame = (byte) 255
else
    currFrame = (byte) 0

Answer 5

It is the conditional operator.

Answer 6

This is a ternary operator (see MSDN). It follows the following syntax:

result = condition ? result_if_condition_true : result_if_condition_false