C# is an Object-oriented programming language. C# comes with simplicity, expressiveness and great performance to meet the programmer productivity.
Introduction
In previous articles, we have seen var and
expressions in C#. Now let's take a look into statements in
C# in this chapter.
Objective
The main objective of this article is to know briefly about the statements and its types that are used in
C#.
Statements
Statements are the actions of the program which are expressed in. Common actions include
methods
,
variables
,
values
etc.
Execution order of statements in a program is called as flow of control (execution).
Statement block:
A series of statements which are placed in the flower braces that are '{
' and '}
' is known as Statement block.
It can contain nested blocks.
Declaration Statements:
It declares a new
variable or
constant
with an expression. For variable, it assigns a value and for
constant
, the assignment is required.
Example:int a = 4;
string name = "krishna";
We can also declare multiple variables of the same type in a single
expression.
For example,
int a = 4, b = 5;
bool in = true, out = false;
Constant declaration is similar to
variable
declaration but, it cannot be changed after the declaration.
For example,
const int a = 4;
a = a + 12; // This will give compile-time error
Expression statements:
These are the valid statements in which they must change the state (variable) or call some other function that might change the state.
Different types of expression statements are,
- Assignment expressions
- Increment and decrement expressions
- Method call expressions
- Object instantiation expressions.
Examples of different types of expressions are,
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Man
{
class Program
{
static void Main()
{
// Declaring variables
int a, b;
StringBuilder sb;
//Expression statements
a = 2 * 3; // Assignment expression
a++; // Increment expression
b = Math.Min(a, 8); // Compares and finds the minimum value
Console.WriteLine(b); // Method call expression
a--; // Decrement expression
b = Math.Max(a, 5); // Compares and finds the maximum value
Console.WriteLine(b); // Method call expression
sb = new StringBuilder(); // Assignment expression
new StringBuilder(); // Object instantiation expression
}
}
}
In the above code we have clearly mentioned the type of expression statements.
Note: please read comments in the code.
Output of this code will be,
Selection statements:
There are so many selection statements in C# such as if
, else
, case
, switch
etc.
if:Let's have an example code that explains about
if
statement in c#,
int a = 5, b = 5;
if (a == b)
{
Console.WriteLine("Both are equal"); // prints "Both are equal" in the console
}
The above code snip executes the statement because both
a
and
b
are equal.
else:
else is the statement block that executes after the
if block (if condition of
if block is false).
For example,
int a = 4, b = 5;
if (a == b)
{
Console.WriteLine("Both are equal");
}
else
{
Console.WriteLine("Not equal"); // Prints this one
}
The above code first check's the
if statement and then it enters into the
else block.
switch, case:switch
statement is used to execute the
switched section from the list (
case
). Let's take an example,
string Fruit = "Mango";
switch (Fruit)
{
case "Mango":
Console.WriteLine(Fruit);
break;
case "Tomato":
Console.WriteLine("Not Fruit");
break;
default:
Console.WriteLine("Default");
break;
}
Iteration statements:
Iteration statements are used to create the loops. Similar to selection statements, iteration statements are also used in many cases where looping and iterating is needed.
do, while:
do
statement executes the block of statements repeatedly until it gets false evaluation. For example,
static void Main()
{
int a = 5, b = 7;
do
{
Console.WriteLine(a);
a++;
}
while (a <= 10);
}
In the above code,
do loops repeatedly until
a
becomes
10
because we have given '
a <= 10
' in the while statement.
for:for
is similar to do but it iterates without using any other statements like
while.
Example,
for (int i = 0; i <= 10; i++)
{
Console.WriteLine(i); // prints 0 to 10
}
foreach:This is one of the important statement used in
C# and
.NET frameworks as they represent the list of elements which are
enumerable.
- It repeats all the embedded statements in a group for each element in an array or an object collection.
- It cannot be used to add or remove the items from the source (for loop does that).
All the embedded statements continue to execute for the each element of an object or an array. After that, the control is transferred to the next statement following the foreach block.
- We can also use he
break
keyword to break out of the loop. - We can use
continue
keyword to go to the next iteration in the loop. - It can also be exited by other statements such as
return
, throw
(jump statements) etc.
Example,
foreach (char c in "Hello") // c is the iteration variable in the statement
{
Console.WriteLine(c); // prints all the characters of the string.
}
Jump statements:
Jump statements are used to perform the
branching operations in
C#.
break
,
continue
,
return
,
throw
and
goto
are the jump statements used in
C#.
break:break is used to terminate the execution at that point (that function).
Example,
for (int i = 0; i <= 10; i++)
{
if (i == 3)
{
break; // It stops terminates the execution at i=3 and prints the before executed outputs
}
Console.WriteLine(i);
}
In the above code,
i
prints
0
,
1
and
2
and terminates the execution.
continue:
continue is used to start the execution at certain point as shown in the below example,
for (int i = 0; i <= 10; i++)
{
if (i < 5)
{
continue; // It continues the execution at i=4 and prints the after executed outputs
}
Console.WriteLine(i);
}
The above code prints the values from
5
as we given '
i < 5
' in the
if statement.
return:
return statement exits the method by returning an expression of the return
type for a non-void method. Example,
static decimal Percentage(decimal b)
{
decimal a = b*100m;
return a;
}
throw:It throws an exception that indicates an occurred error. It is an object derived from
System.Exception.
Example,
throw new ArgumentNullException();
goto:
goto statement transfers the execution of program to another label directly.
Syntax is,
goto statement-label; // for normal statements
and,
goto case case-constant; // for switch statement
- In switch-case statements, it transfers the execution to another case in a switch block.
- It also used to get out from the deep nested loops.
Example for goto statement,
int a = 5;
Begin:
if (a <= 10)
{
Console.WriteLine(a + "");
a++;
goto Begin;
}
Conclusion
In this article, we have seen different types of statements that are used in C#. Hope you understand.
Thanks for reading,
Regards,
Krishna.