C# Global Variable | C# Variable - c# - c# tutorial - c# net
What is variable in C# ?
- A variable is a name of memory location. It is used to store data. Its value can be changed and it can be reused many times.
- It is a way to represent memory location through symbol so that it can be easily identified.
- The basic variable type available in C# can be categorized as:
| Variable Type | Example |
|---|---|
| Decimal types | decimal |
| Boolean types | True or false value, as assigned |
| Integral types | int, char, byte, short, long |
| Floating point types | float and double |
| Nullable types | Nullable data types |
Syntax to declare a variable:
type variable_list;- The example of declaring variable is given below:
- int i, j;
- double d;
- float f;
- char ch;
- Here, i, j, d, f, ch are variables and int, double, float, char are data types.
- We can also provide values while declaring the variables as given below:
- int i=2,j=4; //declaring 2 variable of integer type
- float f=40.2;
- char ch='B';
Rules for defining variables
- A variable can have alphabets, digits and underscore.
- A variable name can start with alphabet and underscore only. It can't start with digit.
- No white space is allowed within variable name.
- A variable name must not be any reserved word or keyword e.g. char, float etc.
Valid variable names
- int x;
- int _x;
- int k20;
Invalid variable names:
- int 4;
- int x y;
- int double;
