Operators Precedence and Associativity in C Language

Spread the love
Precedence-and-Associativity-of-Operators-in-C language

Introduction:

We have discussed about the Operators in C Programming language so far. But what if we have more than one operator in an expression. Then how to evaluate such kind of expressions. So to overcome this problem we have Operators Precedence and Associativity in C Language.

Operators Precedence and Associativity in C :

According to the language specification, Each and every Operator is given a precedence level. So Higher precedence operators are evaluated first after that the next priority or precedence level operators evaluated, so on until we reach finish the expression.

We have different precedence levels for different operators. and one precedence level can have multiple operators.

For example, Multiplication ( *), Division ( /) and Modulo division ( %) have the same precedence level.

So by using the Precedence of the Operators, We can decide which operator should be evaluated first, But what if we get the expression with more than one operator from the same precedence level?

If we get multiple operators from the Same precedence level, Then we use the Operators Associativity to determine which operation to do first.

If the Operators precedence is same, Then depending upon the operators associativity we will evaluate the expression. So Associativity is kind of tie-breaker (🎾) if Precedence is equal.

📢 If you get more than one operator from the same precedence level, Then use the Associativity to evaluate the expression

Operators Precedence and Associativity in C Table :

LevelSymbolDescriptionAssociativity
1++
– –
( )
[ ]
->
.
Prefix increment
Prefix decrement
Function call and subexpression
Array subscript
Structure pointer
Structure member
left to right
2!
~

+
(type)
*
&
sizeof
Logical negation ( Logical NOT )
1’s complement
Unary negation
Unary plus
Type cast
Pointer dereference
Address of Operator
Sizeof Operator
right to left
3*
/
%
Multiplication
Division
Modulus (integer remainder)
left to right
4+
Binary Addition
Binary Subtraction
left to right
5<<
>>
Bitwise left shift
Bitwise right shift
left to right
6<
<=
>
>=
Less than
Less than or equal to
Greater than
Greater than or equal to
left to right
7==
!=
Equality
Not equal
left to right
8&Bitwise ANDleft to right
9^Bitwise exclusive OR (XOR)left to right
10|Bitwise inclusive ORleft to right
11&&Logical ANDleft to right
12||Logical inclusive ORleft to right
13?:Conditional Operatorright to left
14=
+=
-=
*=
/=
%=
<<=
>>=
&=
^=
|
Assignment
Compound Addition
Compound subtraction
Compound multiplication
Compound division
Compound modulus
Compound bitwise left shift
Compound bitwise right shift
Compound bitwise AND
Compound bitwise exclusive OR
Compound bitwise OR
right to left
15,
++
– –
Sequence point (list separator)
Postfix increment
Postfix decrement
left to right

Example to deministrate Operators Precedence and Associativity:

For example, If you have a expression like below.

10 * 40 / 20 % 6

Here we have three Operators, Multiplication * , Division / and Modulo Division %.

So according to above Precedence and Associativity table, We can see these three operators have the same precedence level. So we need to depend on the Associativity.

The associativity of multiplication, Division, and Modulo division operators is from left to right. So we need to evaluate the above expression from left to right.

The first operation will be,

10 * 40 result is 400 and expression became 400 / 20 % 6

Now we need to evaluate 400 / 20which is equal to 20.

The expression became 20 / 6 , The result of this expression is 2.

The final result is 2.

For the 10 * 40 / 20 % 6 Expression, We got the result as 2. So Let’s write a C Program to verify the result.

Example Program : Precedence and Associativity in C Language:

Output:

As you can see from the above output, The value of 10 * 40 / 20 % 6 Expression is 2.

So by using above Precedence and Associativity of Operators, We can evaluate any kind of complex expressions. If you are confused with difficult expressions, Please look at the Precedence and associativity table to evaluate expression.

Related Reading:

Venkat

Hi Guys, I am Venkatesh. I am a programmer and an Open Source enthusiast. I write about programming and technology on this blog.

You may also like...

4 Responses

  1. May 25, 2021

    […] Precedence of Operators […]

  2. June 20, 2021

    […] Precedence of Operators […]

  3. July 16, 2021

    […] 📢 As we are presently looking at arithmetic operators, Below table contains only arithmetic operators priority and associativity. To know the full list of Operators Precedence and Associativity – Operators Precedence and Associativity in C Language – SillyCodes […]

  4. July 19, 2021

    […] Increment Operator have Highest priority than all Binary Operators. Because Unary operators have higher priority than Binary operators. You can see Full priority table here C operators Priority table. […]

Leave a Reply