IP Week 2 C/C++ Overview

Which variable(s) declaration is (are) incorrect?

• int 4ever;

• int hello-world;

• int _Mystar;

• int forever;

Answer explanation

The declaration 'int 4ever;' is incorrect because variable names cannot start with a digit. 'int hello-world;' is also incorrect due to the use of a hyphen, which is not allowed in variable names. The other declarations are valid.

What is the size of the 'bool' data type in C++?

• 2 bytes

• 4 bytes

• 1 byte

• 1 bit

Answer explanation

In C++, the 'bool' data type is typically 1 byte in size. This allows it to store two values: true and false. While it could theoretically be represented with just 1 bit, memory alignment and efficiency lead to it being allocated 1 byte.

What is the size of the 'char' data type in C++?

• 1 byte

• 4 bytes

• 2 bytes

• 8 bytes

Answer explanation

In C++, the 'char' data type is defined to be 1 byte in size. This is a standard size across most platforms, allowing it to represent a single character in memory.

Evaluate the following expression in C/C++:

true && false

• true

• false

Answer explanation

In C/C++, the expression 'true && false' uses the logical AND operator. Since one operand is false, the entire expression evaluates to false. Therefore, the correct answer is 'false'.

Evaluate the following expression in C/C++:

! ( 5 > 3 )

• true

• false

Answer explanation

The expression evaluates to !(true) since 5 > 3 is true. The logical NOT operator '!' negates true to false. Therefore, the correct answer is false.

What is the result of the following expression:

15 / 4

• 3.75

• 4

• 3

• 15

Answer explanation

The expression 15 / 4 equals 3.75. However, the correct answer choice provided is 3, which is the integer part of the division. Thus, the answer is 3.

What is the result of the following expression:

15 / 4.0

• 3.75

• 4

• 3

• 1

Answer explanation

The expression 15 / 4.0 divides 15 by 4.0, resulting in 3.75. Since 4.0 is a floating-point number, the division yields a decimal result, making 3.75 the correct answer.

What is the result of the following expression:

15 / 4 * 1.0

• 3.75

• 4

• 3

• 1

Answer explanation

The expression 15 / 4 * 1.0 evaluates to 3 x 1.0 = 3.0, but since it is often implicitly converted to an integer for display, it may appear simply as 3 when printed.

What is the result of the following expression:

15 * 1.0 / 4

• 3.75

• 3

• 15

• 1

Answer explanation

One operand in the division is a floating-point type leads to floating-point type result.

What is the result of the following expression in C/C++:

15 % 4.0

• Error

• 3

• 4

• 1

Answer explanation

In C/C++, the modulus operator (%) requires both operands to be integers. Since 4.0 is a floating-point number, the expression 15 % 4.0 results in a type error, making 'Error' the correct answer.