C# Variables & Operators with Example

C# Variables

A variable is a name given to a storage area that is used to store values of various data types. Each variable in C# needs to have a specific type, which determines the size and layout of the variable’s memory.

For example, a variable can be of the type String, which means that it will be used to store a string value. Based on the data type, specific operations can be carried out on the variable.

For instance, if we had an Integer variable, then operations such as addition and subtraction can be carried out on the variable. One can declare multiple variables in a program.

Let’s look at a quick example of the declaration of multiple variables of different data types.

In our example, we will define two variables, one of the type ‘string’ and the other of the type ‘Integer’. We will then display the values of these variables to the console. For each example, we will modify just the main function in our Program.cs file.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DemoApplication
{
 class Program 
 {
  static void Main(string[] args) 
  {
   String message="The value is ";
   Int32 val=30;
   
   Console.Write(message+val);
   Console.ReadKey();
  }
 }
}

Code Explanation:-

1. A variable of the data type String is declared. The name of the variable is ‘message’. The value of the variable is “The value is “.
2. A variable of the data type Integer (Int32) is declared. The name of the variable is ‘val’. The value of the variable is 30.
3. Finally the Console.write statement is used to output both the value of the String and Integer variable.

If the above code is entered properly and the program is executed successfully, the following output will be displayed.

Output:

From the output, you can see that the values of both the string and integer variable are displayed to the console.

Now that variables can hold values, the next step is to act on those values. Operators are used to perform operations on values of various data types. For example, to perform the addition of 2 numbers, the + operator is used.

Let’s see the table of operators available for the various data types.

C# Operators

Arithmetic Operators

These are operators used for performing mathematical operations on numbers. Below is the list of operators available in C#.

Relational Operators

These are operators used for performing Relational operations on numbers. Below is the list of relational operators available in C#.

Logical Operators

These are operators used for performing Logical operations on values. Below is the list of operators available in C#.

Let’s look at a quick example of how the operators can be used in .NET.

In our example, we will define 2 Integer variables and one Boolean variable. We will then perform arithmetic, relational, and logical operations on them.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DemoApplication
{
 class Program 
 {
  static void Main(string[] args) 
  {
   Int32 val1 = 10,val2 = 20;
   bool status = true;
   
   Console.WriteLine(val1 + val2);
   Console.WriteLine(val1 < val2);
   Console.WriteLine(!(status));
   Console.ReadKey();
  }
 }
}

Code Explanation:-

1. Two Integer variables are defined, one being val1 and the other being val2. These will be used to showcase relational and arithmetic operations. A Boolean variable is defined to showcase logical operations.
2. An example of the arithmetic operation is shown wherein the addition operator is carried out on val1 and val2. The result is written to the console.
3. An example of the relational operation is shown wherein the less than operator is carried out on val1 and val2. The result is written to the console.
4. An example of the logical operation is shown, wherein the logical operator (!) is applied to the status variable. The logical NOT operator reverses the current value of any Boolean value. So if a Boolean value is ‘true’, the logical NOT will return the value ‘false’ and vice versa. In our case since the value of the status variable is ‘true’, the result will show ‘false’. The result is written to the console.

If the above code is entered properly and the program is executed successfully, the output will be displayed.

Output:

C# Assignment Operators

Assignment operators store the result of an expression in a variable. The basic assignment operator is the single equals sign, and C# also provides compound operators that combine assignment with an arithmetic or bitwise operation. These shorthand forms keep update statements short and easy to read.

For example, writing count += 5 is a shorter way to write count = count + 5. Compound assignment operators work with every arithmetic operator and with the bitwise operators as well, so they appear often inside loops and counters where a value is updated repeatedly.

C# Bitwise Operators

Bitwise operators act on the individual bits of integer values rather than on the whole number. They are useful for low-level tasks such as setting flags, masking values, and performing fast multiplication or division by powers of two.

For instance, the expression 5 & 3 compares the bits of both numbers and returns 1. Because a single left shift doubles a value, bitwise operators can make some calculations faster than their arithmetic equivalents, which matters in graphics and embedded code.

C# Operator Precedence and Associativity

When an expression contains several operators, C# does not simply evaluate them from left to right. Operator precedence sets the order in which different operators run, and associativity decides the order when two operators share the same precedence.

• Precedence: Multiplication and division run before addition and subtraction, so 2 + 3 * 4 gives 14, not 20.
• Left associativity: Most binary operators group from left to right, so a – b – c is evaluated as (a – b) – c.
• Right associativity: The assignment and conditional operators group from right to left, so x = y = z assigns z to y first.
• Parentheses: Wrapping part of an expression in parentheses overrides the default order and makes the intended calculation clear.

Relying on parentheses instead of memorizing the full precedence table keeps complex expressions readable and helps prevent subtle calculation bugs.

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