You can enclose any operand in parentheses without changing the type or value of the enclosed expression. For example, in the expression:
( 10 + 5 ) / 5
the parentheses around 10 + 5 mean that the value of 10 + 5 is evaluated first and it becomes the left operand of the division (/) operator. The result of ( 10 + 5 ) / 5 is 3. Without the parentheses, 10 + 5 / 5 would evaluate to 11.
Although parentheses affect the way operands are grouped in an expression, they cannot guarantee a particular order of evaluation in all cases. For example, neither the parentheses nor the left-to-right grouping of the following expression guarantees what the value of i will be in either of the subexpressions:
( i++ +1 ) * ( 2 + i )
The compiler is free to evaluate the two sides of the multiplication in any order. If the initial value of i is zero, the whole expression could be evaluated as either of these two statements:
( 0 + 1 + 1 ) * ( 2 + 1 )
( 0 + 1 + 1 ) * ( 2 + 0 )
Exceptions resulting from side effects are discussed in Side Effects.