Operator precedence in C++ - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of mixed arithmetic and bitwise operators

What is the output of the following C++ code snippet?

C++

#include <iostream>
int main() {
    int a = 5, b = 3, c = 2;
    int result = a + b << c;
    std::cout << result << std::endl;
    return 0;
}

A 32

B 14

C 13

D 16

💡 Hint

Remember that '+' has higher precedence than '<<'.

The expression is evaluated as (a + b) << c = (5 + 3) << 2 = 8 << 2 = 32.

❓ Predict Output

intermediate

Output of logical and bitwise operators combined

What is the output of this C++ code?

C++

#include <iostream>
int main() {
    int x = 1, y = 2, z = 3;
    int result = x & y || z;
    std::cout << result << std::endl;
    return 0;
}

A 3

B 0

C 1

D 2

💡 Hint

Check operator precedence between '&' and '||'.

Bitwise AND '&' has higher precedence than logical OR '||'. So x & y is 1 & 2 = 0, then 0 || 3 is true (1). So output is 1.

❓ Predict Output

advanced

Result of complex expression with multiple operators

What is the output of this C++ program?

C++

#include <iostream>
int main() {
    int a = 4, b = 2, c = 3;
    int result = a - b * c >> 1 + 1;
    std::cout << result << std::endl;
    return 0;
}

A -1

B 1

C 0

D 2

💡 Hint

Remember operator precedence: '*' then '-' then '>>' then '+'.

Multiplication first: b * c = 2 * 3 = 6. Then subtraction: a - 6 = 4 - 6 = -2. Then addition in shift amount: 1 + 1 = 2. Then right shift: -2 >> 2. In C++ right shift of negative numbers is implementation-defined but usually arithmetic shift keeps sign, resulting in -1.

❓ Predict Output

advanced

Output of expression with ternary and logical operators

What is the output of this C++ code?

C++

#include <iostream>
int main() {
    int x = 0, y = 5;
    int result = x ? y : y > 3 ? 10 : 20;
    std::cout << result << std::endl;
    return 0;
}

A 5

B 0

C 20

D 10

💡 Hint

Ternary operators associate right to left.

Expression is x ? y : (y > 3 ? 10 : 20). Since x is 0 (false), evaluate y > 3 ? 10 : 20. y=5 > 3 is true, so result is 10.

🧠 Conceptual

expert

Operator precedence and associativity in complex expression

Consider the expression:

int x = 2, y = 3, z = 4;
int result = x + y * z / y - z % x;

Which of the following correctly describes the order in which the operations are performed?

A Multiplication and division first (left to right), then addition and subtraction (left to right), then modulo last

B Multiplication, division, and modulo first (left to right), then addition and subtraction (left to right)

C Addition first, then multiplication and division, then subtraction and modulo

D Modulo first, then multiplication and division, then addition and subtraction

💡 Hint

Check operator precedence table: *, /, % have same precedence and associate left to right.

Multiplication (*), division (/), and modulo (%) have the same precedence and associate left to right, so they are evaluated first in order from left to right. Then addition (+) and subtraction (-) are evaluated left to right.