C++ Basics Quiz

Which operator checks if two values are equal?

• =

• ==

• !=

• <=

What will be printed? int x = 10, y = 20; if (x < y) cout << "Yes"; else cout << "No";

• Yes

• No

• Error

• Nothing

Answer explanation

The condition 'x < y' evaluates to true since 10 is less than 20. Therefore, the program executes the first branch of the if statement, printing 'Yes'.

Which statement correctly checks if n is negative?

• if (n = 0)

• if (n < 0)

• if (n <= 0)

• if (n == 0)

Answer explanation

The correct statement to check if n is negative is 'if (n < 0)'. This condition evaluates to true when n is less than zero, accurately identifying negative numbers. The other options do not correctly check for negativity.

Which keyword is used when the if condition is false?

• elseif

• switch

• else

• continue

Answer explanation

The keyword 'else' is used to define a block of code that executes when the 'if' condition is false. It provides an alternative path in conditional statements.

What is the output if the user enters -5? int value; cin >> value; if (value < 0) value = -value; cout << value;

• -5

• 5

• 0

• Error

Answer explanation

When the user enters -5, the condition 'value < 0' is true, so 'value' is set to -(-5), which is 5. Therefore, the output is 5.

What is the logical AND operator in C++?

• ||

• &&

• !

• &

Answer explanation

The logical AND operator in C++ is represented by '&&'. It evaluates to true only if both operands are true. The other options represent different operations: '||' is OR, '!' is NOT, and '&' is bitwise AND.

Which code correctly checks if a number is even?

• if (n/2)

• if (n % 2 == 0)

• if (n % 2)

• if (n == 2)

Answer explanation

The correct choice is 'if (n % 2 == 0)', which checks if the remainder of n divided by 2 is zero, indicating that n is even. The other options do not correctly determine if a number is even.

In a switch statement, which keyword exits the block after a match?

• exit

• stop

• break

• return

Answer explanation

In a switch statement, the 'break' keyword is used to exit the block after a match is found. It prevents the execution from falling through to subsequent cases, making it the correct choice.

Why does if (a = b) not check equality?

• Because = is assignment, not comparison

• Because C++ doesn't allow equality check

• Because == means assignment

• Because it compares addresses

Answer explanation

The statement 'if (a = b)' uses a single equals sign, which is an assignment operator, not a comparison operator. To check equality, the double equals '==' should be used instead.

Which code prints the larger of two integers a and b?

• if (a > b) cout << b; else cout << a;

• if (a > b) cout << a; else cout << b;

• if (a < b) cout << a; else cout << b;

• None

Answer explanation

The correct code to print the larger of two integers a and b is 'if (a > b) cout << a; else cout << b;'. This checks if a is greater than b, printing a if true, otherwise printing b.