Working with Variables: Numbers
Learn how to store numbers in C#, including whole numbers using decimal, binary, and hexadecimal notation.
Numbers are data on which we want to perform an arithmetic calculation, for example, multiplying. A telephone number is not a number. To decide whether a variable should be stored as a number or not, ask yourself whether you need to perform arithmetic operations on the number or whether the number includes non-digit characters such as parentheses or hyphens to format the number, such as .
In this case, the number is a sequence of characters, so it should be stored as a string.
Storing numbers
Numbers can be natural numbers, such as 42, used for counting (also called whole numbers); they can also include negative numbers, such as -42 (called integers); or they can be real numbers, such as 3.9 (with a fractional part), which are called single-precision or double-precision floating-point numbers in computing. Let’s explore numbers:
Step 1: Use your preferred code editor to add a new "Console App/console project" named Numbers to the Chapter02 workspace/solution.
Select
Numbersas the activeOmniSharpproject if you use Visual Studio Code. When the pop-up warning message says that required assets are missing, click "Yes" to add them.If you use Visual Studio 2022, set the startup project to the current selection.
Step 2: In Program.cs, delete the existing code, and then type statements to declare some number of variables using various data types, as shown in the following code:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net7.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
</Project>
Storing whole numbers
We might know that computers store everything as bits. The value of a bit is either 0 or 1. This is called a binary number system. Humans use a decimal number system. The decimal number system, also known as Base 10, has ten as its base, meaning there are ten digits from 0 to 9.
Although it is the number base most used by human civilizations, other number base systems are popular in science, engineering, and computing. The binary number system, also known as Base 2, has two as its base, meaning there are two digits, and ...
