I'm looking for a quick way to create a list of values in C#. In Java I frequently use the snippet below:
List<String> l = Arrays.asList("test1","test2","test3");
Is there any equivalent in C# apart from the obvious one below?
IList<string> l = new List<string>(new string[] {"test1","test2","test3"});
You can create helper generic, static method to create list:
internal static class List
{
public static List<T> Of<T>(params T[] args)
{
return new List<T>(args);
}
}
And then usage is very compact:
List.Of("test1", "test2", "test3")
IList<string> list = new List<string> {"test1", "test2", "test3"}
If you want to create a typed list with values, here's the syntax.
Assuming a class of Student like
public class Student {
public int StudentID { get; set; }
public string StudentName { get; set; }
}
You can make a list like this:
IList<Student> studentList = new List<Student>() {
new Student(){ StudentID=1, StudentName="Bill"},
new Student(){ StudentID=2, StudentName="Steve"},
new Student(){ StudentID=3, StudentName="Ram"},
new Student(){ StudentID=1, StudentName="Moin"}
};
You can simplify that line of code slightly in C# by using a collection initialiser.
var lst = new List<string> {"test1","test2","test3"};
You can drop the new string[]
part:
List<string> values = new List<string> { "one", "two", "three" };
In C# 3, you can do:
IList<string> l = new List<string> { "test1", "test2", "test3" };
This uses the new collection initializer syntax in C# 3.
In C# 2, I would just use your second option.
A list of values quickly? Or even a list of objects!
I am just a beginner at the C# language but I like using
etc.
There's just too many ways to store items
If you're looking to reduce clutter, consider
var lst = new List<string> { "foo", "bar" };
This uses two features of C# 3.0: type inference (the var
keyword) and the collection initializer for lists.
Alternatively, if you can make do with an array, this is even shorter (by a small amount):
var arr = new [] { "foo", "bar" };
You can do that with
var list = new List<string>{ "foo", "bar" };
Here are some other common instantiations of other common Data Structures:
Dictionary
var dictionary = new Dictionary<string, string>
{
{ "texas", "TX" },
{ "utah", "UT" },
{ "florida", "FL" }
};
Array list
var array = new string[] { "foo", "bar" };
Queue
var queque = new Queue<int>(new[] { 1, 2, 3 });
Stack
var queque = new Stack<int>(new[] { 1, 2, 3 });
As you can see for the majority of cases it is merely adding the values in curly braces, or instantiating a new array followed by curly braces and values.
Source: Stackoverflow.com