The for Loop

Certify and Increase Opportunity.
Be
Govt. Certified ASP.NET Programmer

The for Loop

For loops use an iteration variable. They are ideal when looping over many numbers in order with a definite terminating condition. No collection of elements is required. But we can use the variable to index a separate collection. This iteration variable allows more flexibility than foreach.

Example
This example program loops using the for-loop construct in the C# language. The name of the variable “i” is a convention. Because of this, it is easier for other programmers to understand than unusual variable names in many cases.

The program shows an increment for-loop, a decrement for-loop, a for-loop that adds two the variable, and a for-loop that subtracts two from the variable. The example shows also the exact output of this program when it is executed in the Common Language Runtime.

using System;

class Program
{
static void Main()
{
//
// Shows five ‘for int i’ loops.
//
Console.WriteLine(“— For 1 —“);
for (int i = 0; i < 10; i++)
{
Console.WriteLine(i);
}
Console.WriteLine(“— For 2 —“);
for (int i = 10 – 1; i >= 0; i–)
{
Console.WriteLine(i);
}
Console.WriteLine(“— For 3 —“);
for (int i = 0; i < 10; i += 2)
{
Console.WriteLine(i);
}
Console.WriteLine(“— For 4 —“);
for (int i = 10 – 1; i >= 0; i -= 2)
{
Console.WriteLine(i);
}
Console.WriteLine(“— For 5 —“);
for (int i = 0; i < (20 / 2); i += 2)
{
Console.WriteLine(i);
}
}
}

Output

— For 1 —
0
1
2
3
4
5
6
7
8
9
— For 2 —
9
8
7
6
5
4
3
2
1
0
— For 3 —
0
2
4
6
8
— For 4 —
9
7
5
3
1
— For 5 —
0
2
4
6
8

The for-loop construct is followed by parentheses with three statements separated by semicolons. When the for-loops are encountered, the first of the three statements is executed. The for-loop shown first in the example will first has its “int i = 0” statement executed. The loop will start with its iteration variable set to zero.

Get industry recognized certification – Contact us

Menu