# For Loop

The for loop executes a block of code repeatedly until a specified conditional expression evaluates to false.

Anatomy of for loop:

``````for (initialization; condition; iterator)
{
body
}``````
• initialization – The initialization statement(s) sets the initial condition and run only once before you enter the body of the loop.
• condition – Boolean expression which determines whether the body of the loop should execute again or the loop should exit.
• iterator – Executes after each iteration of the body of the loop.

### Example 1

``````for (int i = 0; i < 5; i++)
{
Console.WriteLine("Number " + i);
}``````

### Output:

``````> Number 0
> Number 1
> Number 2
> Number 3
> Number 4``````
• Only counts to 4 due to the fact that the initial number is 0 meaning that 5 numbers including 0 would reach 4.

### Example 2

``````int j = 0;
for (int i = 0; j < 5; i++)
{
Console.WriteLine("Numbers {0} {1}", i, j);
j++;
}``````

### Output:

``````> Numbers 0 0
> Numbers 1 1
> Numbers 2 2
> Numbers 3 3
> Numbers 4 4``````

### Example 3 – Simplification of Example 2

``````for (int i = 0, j = 0; i < 5 && j < 5; i++, j++)
{
Console.WriteLine("Numbers {0} {1}", i, j);
}``````

### Output:

``````> Numbers 0 0
> Numbers 1 1
> Numbers 2 2
> Numbers 3 3
> Numbers 4 4``````

### Example 4

``````for (int i = 5; i > 0; i--)
{
Console.WriteLine("Number " + i);
}``````

### Output:

``````> Number 5
> Number 4
> Number 3
> Number 2
> Number 1``````

### Example 5

``````// Infinite loop - The loop body is executed infinitely
for (; ;)
{
Console.WriteLine("The universe is infinite");
}

// Anything after infinite loop is reported as "Unreachable code detected" in Visual Studio
Console.WriteLine("Never considered for execution");``````

### Output:

``````> The universe is infinite
> The universe is infinite
> The universe is infinite
> ....
> ....``````

### Example 6

``````int i = 0;
for (; i < 5;)
{
Console.WriteLine("Number " + i);
i++;
}``````

### Output:

``````> Number 0
> Number 1
> Number 2
> Number 3
> Number 4``````