Operator Precedence and Associativity in C

tutorial 21 July 2026 15 min read

Operator Precedence and Associativity in C – Complete Guide with MCQs for CDAC C-CAT

Understanding Operator Precedence and Associativity is essential for the CDAC C-CAT exam. Many questions involve evaluating expressions rather than testing individual operators. The key is knowing which operator is evaluated first.

What is Operator Precedence?

Operator precedence determines which operator is evaluated first when an expression contains multiple operators.

Example:

int x = 10 + 5 * 2;

Evaluation:

10 + (5 * 2)
10 + 10
20

Output:

20

Since * has higher precedence than +, multiplication happens first.

What is Associativity?

When two operators have the same precedence, associativity determines the order of evaluation.

Example:

int x = 20 / 5 * 2;

Both / and * have the same precedence and are left-to-right associative.

20 / 5 = 4
4 * 2 = 8

Output:

8

Precedence vs Associativity

  • Precedence decides which operator gets evaluated first.
  • Associativity decides the direction of evaluation when operators have equal precedence.

Common Precedence Order (Highest → Lowest)

OperatorsAssociativity
()Left to Right
Unary (++ -- ! ~ + -)Right to Left
* / %Left to Right
+ -Left to Right
<< >>Left to Right
< <= > >=Left to Right
== !=Left to Right
&Left to Right
^Left to Right
``Left to Right
&&Left to Right
``Left to Right
?:Right to Left
= += -=Right to Left
,Left to Right

For the C-CAT exam, remembering the order below is usually sufficient:

()
Unary
* / %
+ -
Relational
Equality
Bitwise
Logical
Assignment
Comma

Parentheses Override Precedence

int x = (10 + 5) * 2;
15 * 2
30

Always evaluate expressions inside parentheses first.

Solved Examples

Example 1

int a = 2 + 3 * 4;
3 * 4 = 12
2 + 12 = 14

Output

14

Example 2

int a = 20 - 8 / 2;
8 / 2 = 4
20 - 4 = 16

Output

16

Example 3

int a = 1;
int b = 2;
int c = 3;

a = a && b * c + 3;

Evaluation

b * c = 6
6 + 3 = 9
1 && 9 = 1

Output

a = 1

Arithmetic operators are evaluated before logical operators.

Example 4

int x = 10 > 5 + 3;
5 + 3 = 8
10 > 8
1

Output

1

Example 5

int x = 5 == 2 + 3;
2 + 3 = 5
5 == 5
1

Output

1

Common C-CAT Mistakes

Mistake 1

10 + 2 * 5

Wrong:

(10 + 2) * 5

Correct:

10 + (2 * 5)

Mistake 2

a && b + c

Wrong:

(a && b) + c

Correct:

a && (b + c)

Mistake 3

x = y = z = 5;

Assignment operators are right-to-left associative.

z = 5
y = 5
x = 5

CDAC C-CAT MCQs

MCQ 1

printf("%d", 2 + 3 * 4);

A. 20

B. 14

C. 24

D. 10

Answer: B

MCQ 2

printf("%d", 20 / 5 * 2);

A. 2

B. 4

C. 8

D. 10

Answer: C

MCQ 3

int a = 1;
int b = 2;
int c = 3;

printf("%d", a && b * c + 3);

A. 0

B. 1

C. 9

D. 6

Answer: B

Evaluation

b * c = 6
6 + 3 = 9
1 && 9 = 1

MCQ 4

printf("%d", 5 == 2 + 3);

A. 0

B. 1

C. 5

D. Error

Answer: B

MCQ 5

printf("%d", 10 > 5 + 10);

A. 0

B. 1

C. 5

D. Error

Answer: A

MCQ 6

int x;

x = 5 + 2 > 6;

printf("%d", x);

A. 5

B. 6

C. 1

D. 0

Answer: C

Evaluation

5 + 2 = 7
7 > 6
1

MCQ 7

int x = 10;

x = x > 5 && 3 * 2;

printf("%d", x);

A. 0

B. 1

C. 6

D. 10

Answer: B

MCQ 8

int a;

a = 2 + 3 * 4 > 10;

printf("%d", a);

A. 14

B. 0

C. 1

D. 12

Answer: C

Evaluation

3 * 4 = 12
2 + 12 = 14
14 > 10
1

MCQ 9

int x;

x = 10 == 5 + 5 && 8 > 3;

printf("%d", x);

A. 0

B. 1

C. 5

D. Error

Answer: B

Evaluation

5 + 5 = 10
10 == 10 = 1
8 > 3 = 1
1 && 1 = 1

MCQ 10

int x = 5;

x = x = 2 + 3;

printf("%d", x);

A. 2

B. 3

C. 5

D. Error

Answer: C

Assignment operators associate right to left.

Key Takeaways

  • Precedence determines which operator is evaluated first.
  • Associativity determines the evaluation direction when operators have the same precedence.
  • Parentheses () have the highest precedence and should be used to make expressions clearer.
  • Arithmetic operators are evaluated before relational operators, which are evaluated before logical operators.
  • Assignment operators are right-to-left associative.
  • For CDAC C-CAT, always evaluate expressions step by step rather than trying to compute them mentally in one go.