C OR条件运算符中的条件差异

Question

What is the difference in both of the expressions ? Using brackets or not in this case. What is the difference ?

(!String.IsNullOrEmpty(model.SpouseCitizenType) || !String.IsNullOrEmpty(model.SpouseNomPrenom)) &&
                 String.IsNullOrEmpty(model.SpouseEGN);

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!String.IsNullOrEmpty(model.SpouseCitizenType) || !String.IsNullOrEmpty(model.SpouseNomPrenom) &&
                 String.IsNullOrEmpty(model.SpouseEGN);

Answer 1

Operator AND && has a higher precendence than OR || . So, if we denote conditions used here as 1, 2 and 3, first line is equvalent to

(1 || 2) && 3

and the second

1 || (2 && 3)

For the full list of operators sorted in order of precedence check out this MSDN page