Question

Give a \(\mathrm{C}++\) statement that will increase the value of the variable length by \(8.3 .\) The variable length is of type double.

Short answer

Question: Write a C++ statement that increases the value of a double variable named "length" by 8.3. Answer: `length += 8.3;`

Step-by-step solution

Increase the value of length

To increase the value of the variable length by 8.3, we simply need to add 8.3 to the current value of length and store the result back in length. The C++ statement for this operation is: ```cpp length += 8.3; ```

Key concepts

Programming with C++

When learning to program with C++, grasping the basics of arithmetic operations and how they manipulate variables is essential. C++ is a versatile programming language that allows you to perform operations on data to achieve your software objectives. In C++, arithmetic operations include addition (+), subtraction (-), multiplication (*), and division (/). These operations are used to calculate numerical data, similar to basic mathematics.

Let's look at a sample scenario where we want to compute the total price of items in a shopping cart. If each item costs $10 and you have 5 items, you'd use the multiplication operation to find the total:
double totalPrice = 10 * 5;. This is a clear example of how an arithmetic operation is used in C++ to perform a calculation and store the result in a variable.

Variable Manipulation in C++

In C++, variable manipulation is the process of changing the value stored in a variable. Variables can be thought of as containers for storing data values. For instance, you can store numbers, characters, or even complex data types in these containers. Manipulating variables is a fundamental aspect of programming as it allows you to dynamically control and change data during the execution of a program.

An important aspect of variable manipulation is the assignment operator (=), which is used to assign values to variables. For example, int number = 10; places the value 10 into the variable called 'number'. There are also compound assignment operators, like '+=' used in the provided exercise, to both perform an arithmetic operation and assignment in one step. This is convenient for updating the existing value of a variable without having to rewrite it fully: number += 5; will add 5 to the current value of 'number'.

Incrementing Variables

Incrementing a variable means to increase its value by a certain amount. In the world of C++ programming, incrementing is a common operation, especially in loops and counters. Instead of using the basic assignment and addition operators separately, C++ provides a shortcut to increment the variable's value.

For example, to increase an integer variable 'counter' by 1, we could write counter = counter + 1; or simply counter++; or ++counter;. For incrementing by values other than 1, we use the compound assignment operator '+=', as in the given exercise: length += 8.3;. This efficiently adds 8.3 to the current value of 'length', which is particularly useful when dealing with variables of floating-point types such as 'double', where you might be dealing with non-integer increments.