C# Methods are a set of statements or code blocks to perform a specific operations and may return a value.
These are defined once and are reusable as many times as needed.
Syntax:
( )
{
statements..
}
These are classified into 2 types:
- Static Methods
- Non Static Methods (Instance Methods)
Static Methods:
Methods having static keywords are Static Methods. These methods are accessed with
the class name.
Example:
using System;
namespace SampleProgram {
class MySample {
public static int GetSquare(int r) // static method
{
return r * r;
}
public static void Main(string[] args) {
Console.WriteLine("The Square value is " + MySample.GetSquare(4));
}
}
}
The output will be:
The Square value is 16
Non Static Methods (Instance Methods):
Methods having no static keyword are Instance Methods. These methods are accessed by the object of
the class.
Example:
using System;
namespace SampleProgram {
class MySample {
public int GetSquare(int r) //non static method
{
return r * r;
}
public static void Main(string[] args) {
MySample obj = new MySample();
Console.WriteLine("The Square value is " + obj.GetSquare(4));
}
}
}
The output will be:
The Square value is 16
Method Parameters:
A Method can have 4 different types of parameters, as listed are:
- Value Parameters
- Reference Parameters
- Output Parameters
- Parameter arrays
Value Parameters:
Value type variable stores a copy of the value.
Example:
The Swap does not happen as the value type store the copy of the value.
using System;
namespace SampleProgram {
class MySample {
public static void GetSwapInfo(int a, int b) {
int t = a;
a = b;
b = t;
}
public static void Main(string[] args) {
int p = 10,
q = 20;
MySample.GetSwapInfo(p, q);
Console.WriteLine($ "The Swap Data: {p},{q}");
}
}
}
The output will be:
The Swap Data: 10,20
Ref Parameters:
Ref type variable stores the address of the value.
Example:
The Swap happens as the ref type store the address of the value.
using System;
namespace SampleProgram {
class MySample {
public static void GetSwapInfo(ref int a, ref int b) {
int t = a;
a = b;
b = t;
}
public static void Main(string[] args) {
int p = 10,
q = 20;
//passing reference parameter will swap the data.
MySample.GetSwapInfo(ref p, ref q);
Console.WriteLine($ "The Swap Data: {p},{q}");
}
}
}
The output will be:
The Swap Data: 20,10
Output Parameters:
Output parameters are mainly used in methods to produce multiple returns
values.
Example 3:
using System;
namespace SampleProgram {
class MySample {
public static void GetInfo(int a, out int b) {
b = 50;
}
public static void Main(string[] args) {
int p = 10;
MySample.GetSwapInfo(p, out q);
Console.WriteLine($ "The Data: {p},{q}");
}
}
}
The output will be:
The Swap Data: 10,50
Parameter Arrays:
Pass an array as multiple values to a method parameter.
Example:
using System;
namespace SampleProgram {
class MySample {
public static void PrintAgeInfo(int[] arr) {
foreach(int i in arr) {
Console.WriteLine(i);
}
}
public static void Main(string[] args) {
Int[] ageArr = {
10,
20,
30,
40
};
PrintAgeInfo(ageArr);
}
}
}
The output will be:
10
20
30
40
Anonymous Methods:
An anonymous method is a method that doesn’t have any name.
It is used when the user wants to create an inline method. It uses a delegate keyword to define.
Syntax:
delegate(){
// Code..
};
Example:
using System;
namespace SampleProgram {
class MySample {
public delegate void GetArea(int x, int y);
public static void Main(string[] args) {
GetArea area = delegate(int X, int Y) {
Console.WriteLine($”Area is: {
X * Y
}”);
}
area(20, 30);
}
}
}
The output will be:
Area is:600
