ASP.NET Razor - C# Loops and Arrays
Statements can be executed repeatedly in loops.
For Loops
If you need to run the same statements repeatedly, you can program a loop.
If you know how many times you want to loop, you can use a for loop. This kind of loop is especially useful for counting up or counting down:
For Each Loops
If you work with a collection or an array, you often use a for each loop.
A collection is a group of similar objects, and the for each loop lets you carry out a task on each item. The for each loop walks through a collection until it is finished.
The example below walks through the ASP.NET Request.ServerVariables collection.
Example
<html>
<body>
<ul>
@foreach (var x in
Request.ServerVariables)
{<li>@x</li>}
</ul>
</body>
</html>
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While Loops
The while loop is a general purpose loop.
A while loop begins with the while keyword, followed by parentheses, where you specify how long the loop continues, then a block to repeat.
While loops typically add to, or subtract from, a variable used for counting.
In the example below, the += operator adds 1 to the variable i, each time the loop runs.
Example
<html>
<body>
@{
var i = 0;
while (i < 5)
{
i += 1;
<p>Line @i</p>
}
}
</body>
</html>
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Arrays
An array is useful when you want to store similar variables but don't want to create a separate variable for each of them:
Example
@{
string[] members = {"Jani", "Hege", "Kai",
"Jim"};
int i = Array.IndexOf(members, "Kai")+1;
int len =
members.Length;
string x = members[2-1];
}
<html>
<body>
<h3>Members</h3>
@foreach (var person in
members)
{
<p>@person</p>
}
<p>The number of names
in Members are @len</p>
<p>The person at
position 2 is @x</p>
<p>Kai is now in
position @i</p>
</body>
</html>
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