Question

Write an if statement that prints the message "The number is valid" if the variable temperature is within the range -50 through 150

Short answer

Question: Write an if statement that prints "The number is valid" if the given 'temperature' variable is within the range of -50 to 150. Answer: ``` if -50 <= temperature <= 150: print("The number is valid") ```

Step-by-step solution

Define the condition for the if statement

The condition that needs to be checked is whether the variable temperature is within the range -50 to 150. We can represent this condition as: -50 <= temperature <= 150

Write the if statement

Based on the above condition, we can write the if statement as follows: ```python if -50 <= temperature <= 150: # Add the code to print the required statement here ```

Print the message

Inside the if statement block, include the print function to display the "The number is valid" message as follows: ```python if -50 <= temperature <= 150: print("The number is valid") ``` Now, when the variable temperature is within the specified range, the program will print "The number is valid".

Key concepts

Understanding the If Statement in C++

In C++, an if statement helps you control the flow of a program by making decisions based on conditions. It acts like a gatekeeper that only allows certain pieces of code to execute when specific conditions are met. For example, if you want a program to respond only if a variable meets certain criteria, you'll use an if statement. The basic syntax of an if statement in C++ is: ```cpp if (condition) { // code to execute if condition is true } ``` When the condition evaluates to true, the code inside the braces is executed. If it's false, the program simply skips that block and continues. So, an if statement is crucial for implementing decision-making capabilities in your C++ programs.

Exploring Conditional Logic

Conditional logic forms the backbone of decision-making in programming. Through logical statements, you can devise expressions that evaluate to true or false. In our scenario, the statement evaluating the temperature variable is an example of conditional logic:

• -50 <= temperature <= 150

This checks if the temperature value falls within a specified range. The beauty of using conditional logic lies in its ability to combine multiple conditions using logical operators like and, or, and not. However, in C++, the double condition as seen in this code would be broken into two conditions logically connected, like: ```cpp if (temperature >= -50 && temperature <= 150) { // code } ``` This ensures both conditions are satisfied. Using these logical constructs effectively empowers your programs to handle complex scenarios with ease.

Implementing Range Checking

Range checking is a powerful technique used to verify that a variable falls within a specified boundary. It is particularly important when working with data that must adhere to fixed limits. Consider our task of checking if a temperature is valid. We determine this by defining the acceptable range:

• A temperature between -50 and 150

To implement range checking in your program, you can use an if statement that encloses the defined boundary conditions. This prevents out-of-range values from being unintentionally processed, which might lead to errors. By safeguarding your variables with range checking, you ensure reliability and accuracy in your program's outcomes.

Working with the Temperature Variable

Variables in programming act as placeholders for data your program needs to process. In our case, the temperature variable is a critical piece that represents the data we evaluate against certain conditions. When you define a variable in C++, you assign a type and a name, like so: ```cpp int temperature; ``` Here, int indicates the variable type—an integer in this case, while temperature is the variable's name. Once defined, you can set this variable to hold a value, and then use it for calculations or evaluations in logical statements. When using a variable like temperature, be mindful of its type and the precision of values it holds, as they could affect how your program executes range checking and conditional logic. These subtleties underscore the importance of understanding variable properties in programming.