Variables are storage locations used for storing data. Every variable has a specific type such as int, string, double, etc. that defines the type of values it can hold. C# is a strongly typed language, which means that you must define the data type of a variable before using it.
Variables
C# programming language has various types of variables that are defined with different keywords, for instance:
- int: whole numbers without decimals, for example, 45 or -56.
- double: numbers with decimals, for example, 23.09 or -59.12.
- char: single letters or symbols, for example, ‘g’ or ‘J’. Please note that char values are always surrounded by single quotes.
- string: text values, for example, “ESTUDY 247”. String values are always surrounded by double quotes.
- bool: values that have only two states, either true or false.
Syntax for Variable Declaration:
To declare a variable in C#, use the following syntax:
[Data Type] [Variable Name];
[Data Type] [Variable Name] = [Value];
Example
1. Single Variable Declaration:
To declare a variable, you specify its data type followed by an identifier (variable name). For instance:
int age; // Declare an integer variable named 'age'
age = 30; // Assign a value to 'age'
2. Initializing Variables:
You have the option to both declare and initialize a variable in a single step.
double salary = 34500.83; // Declare and initialize a double variable
3. Multiple Variables of the Same Type:
You can declare several variables of the same data type in a single statement.
int x, y, z; // Declare three integer variables
4. Using Constants in Variables:
Constants are special variables that retain their initial values throughout the program and cannot be modified during its execution.
const double Pi = 3.14; // Declare a constant for Pi
5. String Variables:
A string is a data type used to store text. To declare and initialize a string variable, you can use the following syntax: [variable type] [variable name] = [string value];
string name = "Estudy247"; // Declare and initialize a string
6. Boolean Variables:
Booleans are a data type that represents only two values: true or false.
bool isEmployee = true; // Declare and initialize a boolean
7. Character Variables:
A character is a single unit that can represent a letter, symbol, or digit such as ‘A’, ‘b’, or ‘$’.
char grade = 'B'; // Declare and initialize a character
Please keep in mind the following important points when naming variables in programming:
- Variable names should consist of letters, numbers, and underscores.
- They must start with a letter or underscore, not a number.
- Spaces are not allowed in variable names.
- Avoid using reserved keywords such as ‘int’ and ‘float’ as variable names.
- Once a variable is declared with a particular data type, it cannot be declared again with a different data type.