CSE 20211 โ Fundamentals of Computing I โ Univ. of Notre Dame
09/09/09
Read Chapter 3
Operator Precedence
Different operators in C are +, *, -, /, %,++, --. The latter two take either prefix or postfix form.
Compound operators include +=, /=, *=, -=, %=. For instance, i+=2 implies i = i + 2;
Generally parenthesis can be used to control the precedence order in operators. Expressions in a
parenthesis are evaluated first. When an expression contains more than one parentheses, the
operators located in the innermost pair of parentheses have the highest precedence. For example,
the + has the highest precedence in the statement below.
x = ((a+b)-c/d);
Also we cannot use two consecutive arithmetic operators in an expression between two variables,
lest parentheses are used to separate them. For instance a*-b should be written as a*(-b)
Operator Name # operands Position Associativity Precedence
( parentheses unary prefix L to R 1
) parentheses unary postfix L to R 1
+ positive sign unary prefix R to L 2
- negative sign unary prefix R to L 2
++ post-inc. unary postfix L to R 2
-- post-dec. unary postfix L to R 2
++ pre-inc. unary prefix R to L 2
-- pre-dec unary prefix R to L 2
+= addition and assign binary infix R to L 2
-= sub and assign binary infix R to L 2
*= mult. and assign binary โ โ โ
/= div and assign binary โ โ โ
%= remainder and assign binary โ โ โ
% remainder binary infix L to R 3
* multiply binary โ โ โ
/ division binary โ โ โ
+ add binary โ โ 4
- sub binary โ โ 4
= assignment binary โ R to L 5
