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

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.

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 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.