Precedence is the order in which the
compiler groups operands with operators. The C compiler evaluates
certain operators and their operands before others. If operands
are not grouped using parentheses, the compiler groups them according
to its own rules.
The following lists C operator precedence in highest to lowest precedence:
Table 5-14 C Operator Precedence
Class of operator | Operators | Grouping |
|---|
primary | () [] -> . | left to right |
unary | (type casting) sizeof & (address of) * (dereference) - (reverse sign) ~ ! ++ -- | right to left |
multiplicative | * / % | left to right |
additive | + - | left to right |
shift | << >> | left to right |
relational | < <= > >= | left to right |
equality | == != | left to right |
bitwise AND | & | left to right |
bitwise XOR | ^ | left to right |
bitwise OR | | | left to right |
logical AND | && | left to right |
logical OR | || | left to right |
conditional | ?: | right to left |
assignment | = += -= *=
/= %= >>= <<= &= ^= |= | right to left |
comma | , | left to right |
Precedence
among Operators of Same Class |
 |
Most operators group from the left to the right but some group
from the right to the left. The grouping indicates how an expression
containing several operators of the same precedence will be evaluated.
Left to right grouping means the expression
a/b * c/d
behaves as if it had been written:
(((a/b)*c)/d)
Likewise, an operator that groups from the right to the left
causes the expression
a = b = c
to behave as if it had been written:
a = (b = c)
