How to Initialize a List of Strings (List<String>) with Many String Values

How to initialize a list of strings (Liststring) with many string values

List<string> mylist = new List<string>(new string[] { "element1", "element2", "element3" });

How to initialize ListString object in Java?

If you check the API for List you'll notice it says:

Interface List<E>

Being an interface means it cannot be instantiated (no new List() is possible).

If you check that link, you'll find some classes that implement List:

All Known Implementing Classes:

AbstractList, AbstractSequentialList, ArrayList, AttributeList, CopyOnWriteArrayList, LinkedList, RoleList, RoleUnresolvedList, Stack, Vector

Some of those can be instantiated (the ones that are not defined as abstract class). Use their links to know more about them, I.E: to know which fits better your needs.

The 3 most commonly used ones probably are:

 List<String> supplierNames1 = new ArrayList<String>();
 List<String> supplierNames2 = new LinkedList<String>();
 List<String> supplierNames3 = new Vector<String>();

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Bonus:

You can also instantiate it with values, in an easier way, using the Arrays class, as follows:

List<String> supplierNames = Arrays.asList("sup1", "sup2", "sup3");
System.out.println(supplierNames.get(1));

But note you are not allowed to add more elements to that list, as it's fixed-size.

How can I initialize a C# List in the same line I declare it. (IEnumerable string Collection Example)

var list = new List<string> { "One", "Two", "Three" };

Essentially the syntax is:

new List<Type> { Instance1, Instance2, Instance3 };

Which is translated by the compiler as

List<string> list = new List<string>();
list.Add("One");
list.Add("Two");
list.Add("Three");

How to make a new List in Java

List myList = new ArrayList();

or with generics (Java 7 or later)

List<MyType> myList = new ArrayList<>();

or with generics (Old java versions)

List<MyType> myList = new ArrayList<MyType>();

How to Create and Initialize (in Java) a ListString[] in the same statement? (Editors please NOTE: this *not* the same as just a ListString)

The correct answer was given in the comments (above) by @user16320675 , and this works well. It handles both the creation of the outer List and the internal array of strings. Other answers pointing to a simple Array asList are for simple strings, which is not the question that was asked.

to create a mutable list

final List<String[]> rolesCsv =
     new ArrayList<String[]>Collections.singletonList(new String[]{"Role Name","Description"}));

Otherwise (despite the array, its element, will not be immutable)

final List<String[]> rolesCsv =
      Collections.singletonList(new String[]{"Role Name","Description"})

Initialize list of strings with 2 strings

You would just return a variable of type List. IE:

public async static Task<List<String>> TagMonatJahr()
{
    string var1= String.Empty;
    string var2 = String.Empty;        
    return new List<String>{var1, var2};
}   

why we cannot add values directly in Liststring obj= new Liststring()?

You can't write code like that in a class body

You have 2 options, either set the contents of your list when you declare it

List<string> cities = new List<string>() {"pune", "Mumbai"};

Alternatively you can do what you're currently doing, but move some of your code into the class' constructor

public class ValuesController : ApiController
{
    List<string> cities = new List<string>();

    public ValuesController()
    {
        cities.Add("pune");
        cities.Add("Mumbai");
    }

    // GET api/values
    public IEnumerable<string> Get()
    {
        return cities ;
    }
}

Read more about class constructors here

You might also want to consider making cities a private field

C# how to initialize list with values from different list using lambdas or something else -- need to simplify

Looks like it might be something like

Clinician = new Clinician()
{
   Roles = expectedRolesString.Split(',',';').Select(r => Enum.Parse<RoleModel>(r.Trim())).ToList()
}

or perhaps

Clinician = new Clinician()
{
   Roles = expectedRolesString.Split(new[]{',',';',' '}, StringSplitOptions.RemoveEmptyEntries).Select(Enum.Parse<RoleModel>).ToList()
}

..but I'd have liked to see the input data and enum definition to make sure

Adding a string List to a dictionary, then retrieving it's values

I assume the scenarioContext is declared as Dictionary<string, List<string>>, you can retrieve the value, which is a list in this case, by key. This is how your code would look like:

Option 1

Dictionary<string, List<string>> scenarioContext = new Dictionary<string, List<string>>();

List<string> myList = new List<string>();

myList.Add("Thomas");

myList.Add("Bob");

myList.Add("Andy");

scenarioContext.Add("myList", myList);

List<string> newList = new List<string>();

newList = scenarioContext["myList"];

Update: I just found out that ScenarioContext in SpecFlow has an additional Getter. You are casting the List as string in your last line of code, it should look like this:

NewList  = this.ScenarioContext.Get<List<string>>("myList");

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