Question

What value will be stored in the variable $t$ after each of the following statements executes? A) $t=(12>1):$ _____ B) $t=(2<0):$____ C.) $(5)t=(5=(3\cdot 2)):$___ D) $t=(5-5)$____

Short answer

Answer: After the execution of each statement, the values stored in the variable $t$ are as follows: Statement A: True, Statement B: False, Statement C: False, and Statement D: 0.

Step-by-step solution

Evaluate statement A

For statement A, $t=(12>1):$ We are given a condition to check if 12 is greater than 1. Since 12 is greater than 1, the condition is true.

Store the result of statement A

As the condition in statement A is true, the value stored in variable $t$ will be true. So, $t=(12>1):$ True

Evaluate statement B

For statement B, $t=(2<0):$ We are given a condition to check if 2 is less than 0. Since 2 is greater than 0, the condition is false.

Store the result of statement B

As the condition in statement B is false, the value stored in variable $t$ will be false. So, $t=(2<0):$ False

Evaluate statement C

For statement C, $t=(5=(3\cdot 2)):$ We are given a condition to check if 5 is equal to the result of 3 multiplied by 2. Since $3\cdot 2=6$, the condition is false.

Store the result of statement C

As the condition in statement C is false, the value stored in variable $t$ will be false. So, $t=(5=(3\cdot 2)):$ False

Evaluate statement D

For statement D, $t=(5-5)$ In this statement, we need to compute the result of 5 minus 5 which is 0.

Store the result of statement D

As the result of the expression in statement D is 0, the value stored in variable $t$ will be 0. So, $t=(5-5)$: 0

Key concepts

Boolean Logic in C++

In C++, boolean logic is the backbone of decision-making processes. It is the part of the language that allows us to evaluate conditions that are either true or false. Boolean expressions use Boolean operators such as AND (&&), OR (||), and NOT (!) to combine or negate conditions. For example, if you need to check if a number x is greater than 10 and less than 20, you could write (x > 10 && x < 20).

Every comparison in C++ returns a Boolean value: either true or false. This value can then be used directly in conditional statements such as if, while, and for loops. The results of these comparisons often determine the direction in which the program will proceed by executing or skipping certain sections of code based on the truth value of conditions.

Relational Operators in C++

Relational operators are used in C++ to compare values. They are a subset of operators that return a boolean value after evaluating a relationship between two operands. The core relational operators in C++ include:

• > for 'greater than'
• < for 'less than'
• >= for 'greater than or equal to'
• <= for 'less than or equal to'

These operators allow for conditions in control flow statements to compare numerical values, and can be combined with the assignment operator to store the boolean result in a variable.

For instance, if we consider the expression (12 > 1) in our exercise, the relational operator > checks if 12 is greater than 1. As 12 is indeed greater, the expression evaluates to true, and this boolean value gets assigned to the variable t. Relational operators are fundamental in loops and decision-making constructs where multiple conditions might need to be evaluated to determine the course of action.

Equality Operators in C++

Equality operators in C++ are a special type of relational operators focused specifically on testing equality and inequality between two operands. There are two main equality operators:

• == for 'equal to'
• != for 'not equal to'

These operators are crucial when a program needs to make decisions based on whether certain values are the same or different. When used, they similarly return a boolean value of true or false.

Looking at the example from our exercise, (5 == (3 * 2)), the equality operator == is used to assess whether the left-hand side is equal to the right-hand side. Since 3 * 2 equals 6, which is not equal to 5, the result is false, and so the variable t would be assigned the value false. It’s important to make a clear distinction between the double-equals operator ==, which checks for equality, and the single equals =, which is used for assignment.