On every children add 1 (+1) Umbraco Razor - razor

Question

In the code below i need it to add (+1) on every children on data-slide-index="0".
Starting at 0 and then 1,2,3,4,5
It should look like this:
data-slide-index="0"
data-slide-index="1"
data-slide-index="2"
I am thinking something like this.
int theCount = 0;
theCount += 1; // Adds 1 to count
But I dont know how to use it correctly in the code.
#foreach (var image in #Model.Children)
{
foreach (dynamic d in image.imageDampSingle)
{
<a data-slide-index="0" href="#DAMP_Helper.GetImageCropperUrl(d, "projectSingle")"><img src="#DAMP_Helper.GetImageCropperUrl(d, "projectSingleThumb")" title="#Model.captionText" alt="#d.Image.nodeName" /></a>
Or is there a easier / another way to do this?
Thanks in advance!
//René

Answer 1

Razor is just a view engine, you are using C# code in there to do some logic operation. Recursive methods are algorithmic operations that have the capability to call themselves until a certain condition is satisfied. You can use a helper in this case to achieve that. An example for your case:
#helper DoSomething(IEnumerable<Something> myList)
{
foreach (var item in myList)
{
#item.CertainProperty
#if (item.Children.Any())
{
#DoSomething(item.Children)
}
}
}
Learn and read about recursion, and a whole new world of fundamental concepts will appear.
http://en.wikipedia.org/wiki/Recursion_(computer_science)
http://learnyousomeerlang.com/recursion
It's a fundamental topic, I was actually programming some snippets right now when I read this topic, where's other example in Python:
def contaVogais(cadeia):
if not cadeia:
return 0
return (1 if cadeia[0] in 'aeiou' else 0) + contaVogais(cadeia[1:])
As you can see by the examples, recursive solutions are usually more elegant, but in some cases might have a decrease the code performance.

Answer 2

I found a solution. See below:
#{
var countNum = -1;
}
#foreach (var image in #Model.Children)
{
{
countNum += 1;
}
foreach (dynamic d in image.imageDampSingle)
{
<a data-slide-index="#countNum" href="#DAMP_Helper.GetImageCropperUrl(d, "projectSingle")"><img src="#DAMP_Helper.GetImageCropperUrl(d, "projectSingleThumb")" title="#Model.captionText" alt="#d.Image.nodeName" /></a>
}
}
You are welcome to comment on it regarding improvement of the code.
//René