运算符的优先级级别搞错的痛苦代价

Precedence Operator Description Associativity 1 :: Scope resolution Left-to-right 2 ++   -- Suffix/postfix increment and decrement () Function call [] Array subscripting . Element selection by reference -> Element selection through pointer 3 ++   -- Prefix increment and decrement Right-to-left +   − Unary plus and minus !   ~ Logical NOT and bitwise NOT (type) Type cast * Indirection (dereference) & Address-of sizeof Size-of new, new[] Dynamic memory allocation delete, delete[] Dynamic memory deallocation 4 .*   ->* Pointer to member Left-to-right 5 *   /   % Multiplication, division, and remainder 6 +   − Addition and subtraction 7 <<   >> Bitwise left shift and right shift 8 <   <= For relational operators < and ≤ respectively >   >= For relational operators > and ≥ respectively 9 ==   != For relational = and ≠ respectively 10 & Bitwise AND 11 ^ Bitwise XOR (exclusive or) 12 | Bitwise OR (inclusive or) 13 && Logical AND 14 || Logical OR 15 ?: Ternary conditional Right-to-left = Direct assignment (provided by default for C++ classes) +=   −= Assignment by sum and difference *=   /=   %= Assignment by product, quotient, and remainder <<=   >>= Assignment by bitwise left shift and right shift &=   ^=   |= Assignment by bitwise AND, XOR, and OR 16 throw Throw operator (for exceptions) 17 , Comma Left-to-right

自以为 << 的优先级高于 + ，导致错误的结果！

short c = (short)( (high << 8) + low);

short d = (short)( high << 8 + low);

short f = (short)( high << (8 + low));

// d与f结果一致，