Visual Programming Lectures using Visual Studio 2015 C# Windows Form Application Lecturer: Saman M. Almufti / Kurdistan Region, Nawroz University facebook: https://www.facebook.com/saman.malmufti

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++)
{
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