Which side (left or right) of && (and) operator evaluated in C++

Question

Which order is the and && operator evaluated

For example the following code

if (float alpha = value1-value2 && alpha > 0.001)
    //do something

threw an exception that alpha is being used without being initiated. I thought the expression left of the && would always initiate the value of alpha first, but it seems I may be wrong

Any idea?

Thanks

Answer 1

This gets parsed as:

if (int alpha = (value1-value2 && (alpha > 0.001)))

... because && has a higher "parsing precedence" than = -- which is probably not what you want. Try:

int alpha = value1-value2; 
if (alpha && (alpha > 0.001))