The document explains C# loop statements, detailing how to execute code blocks multiple times using 'for', 'while', and 'do while' loops. It provides several examples demonstrating the implementation of these loops, including showing messages and populating list boxes with numbers and characters. The document is instructional and focused on practical usage in C# programming.

3. C# LOOPS STATEMENTS
There may be a situation, when you need to execute a block of code several number
of times. In general, the statements are executed sequentially: The first statement in a
function is executed first, followed by the second, and so on.
A loop statement allows us to execute a statement or a group of statements multiple
times
do
{
statement;
}
while(condition)
For(start;stop;step)
{
statement;
}
while(condition)
{
statement;
}

4. For(Initial Value; Condition; Steps)
{
statements;
}
The For loop statement is used in C# to execute a code
multiple times
FOR LOOP

5. private void button1_Click(object sender, EventArgs e)
{
for(int i=0;i<=4;i++)
{
MessageBox.Show("hello");
}
}
EXAMPLE 1
User for loop to show hello 5 times in a messagebox

6. private void button1_Click(object sender, EventArgs e)
{
for(int i=1;i<=10;i++)
{
MessageBox.Show(i.ToString());
}
}
Use for loop to show from 1 to 10 in a messagebox
EXAMPLE 2

7. private void button1_Click(object sender, EventArgs e)
{
for(int i=1;i<=100;i++)
{
listBox1.Items.Add(i.ToString());
}
}
EXAMPLE 3
Use for loop to insert numbers from 1 to 100 to a list box

8. private void button1_Click(object sender, EventArgs e)
{
for(char i='A';i<='Z';i++)
{
listBox1.Items.Add(i);
}
}
EXAMPLE 4
Use for loop to insert upper case alphabet to a list box

9. private void button1_Click(object sender, EventArgs e)
{
for(int i=100;i>=0;i--)
{
listBox1.Items.Add(i.ToString());
}
}
EXAMPLE 5
Use for loop to insert numbers from 100 to 1 to a list box

10. private void button1_Click(object sender, EventArgs e)
{
for (int i=1;i<=100;i++)
{
if(i%2==0)
{
listBox1.Items.Add(i.ToString());
}
}
}
EXAMPLE 6
Use for loop to insert even numbers from 1 to 100 to a list
box

11. private void button1_Click(object sender, EventArgs e)
{
for (int i=0;i<=100;i++)
{
if(i%5==0)
{
listBox1.Items.Add(i.ToString());
}
}
}
EXAMPLE 7
Using for loop insert {0,5,10,15,20,15,30,35,…..100}to
listbox
private void button1_Click(object sender, EventArgs e)
{
for (int i=0;i<=100;i=i+5)
{
listBox1.Items.Add(i.ToString());
}
}

12. while(condition)
{
statement(s);
}
The while statement continually executes a block of statements until
a specified expression evaluates to false . The expression is
evaluated each time the loop is encountered and the evaluation result
is true, the loop body statements are executed.
WHILE LOOP

13. private void button1_Click(object sender, EventArgs e)
{
int i = 0;
while(i<=4)
{
MessageBox.Show("hello");
i++;
}
}
EXAMPLE 8
Use while loop to show hello 5 times

14. private void button1_Click(object sender, EventArgs e)
{
int i = 1;
while(i<=10)
{
if (i % 2 == 0)
{
listBox1.Items.Add(i.ToString());
}
i++;
}
}
EXAMPLE 9
Use while loop to add even number 1:10 to list box

15. Do
{
statement(s);
}
while(condition)
The Do while statement continually executes a block of statements
until a specified expression evaluates to false . The expression is
evaluated each time the loop is encountered and the evaluation result
is true, the loop body statements are executed.
DO WHILE LOOP

16. private void button1_Click(object sender, EventArgs e)
{
int i = 0;
do
{
MessageBox.Show("hello");
i++;
}
while (i <= 4);
}
EXAMPLE 10
User Do whileto show hello 5 times in a messagebox