Extracting text from an IEnumerable<T>

Question

I have a IEnumerable<T> collection with Name, FullName and Address.

The Address looks like this:

Street1=54, Street2=redfer street, Pin=324234
Street1=54, Street2=fdgdgdfg street, Pin=45654
Street1=55, Street2=tryry street, Pin=65464

I want to loop through this collection and print only those Names, FullNames whose Street1=54

How can i do it in LINQ?

Ok I was able to do this to extract Street1 of the Address

coll.Address.Split(",".ToCharArray())[0]returns me Street1=54 .

Now how do I add this to the condition and print only those Name, FullName whose Street1=54

Answer 1

Try this

var result = collection.Where(x => x.Address.Street1==54);
foreach ( var cur in result ) {
  Console.WriteLine(var.Name);
}

Answer 2

Select the correct list of :

IList<T> matches = myListOfEnumerables.Where(m => m.Street1 == 54).ToList();

Then loop and print.

Answer 3

Actually the record looks like this:

{Name="Jan" FullName="Kathy Jan" Address="Street1=54, Street2=redfer street, Pin=324234"}

I have to loop through this collection and print only those Names, FullNames whose Street1=54

Answer 4

If the updated information is accurate, you should change the way you store the data.

It looks like you've packed the address information into a string. Why not store it as an object. In fact, why not just as more fields in the same object as the Name and FullName? (and why duplicate the first-name information?)

public class Person
{
    public string FirstName, LastName, Street1, Street2, Pin;
}

IEnumerable<Person> persons = GetAllPersonsSomehow();

foreach (Person person in persons.Where(p => p.Street1 == "54"))
    Console.WriteLine(person.LastName + ", " + person.FirstName);

Assuming you have to keep the address information in a string, you need a parser for it.

public static IDictionary<string, string> GetAddressFields(string address)
{
    return address.Split(',').ToDictionary(
                s => s.Substring(0, s.IndexOf('=')).Trim(),
                s => s.Substring(s.IndexOf('=') + 1).Trim());
}


foreach (Person person in persons.Where(p => 
                GetAddressFields(p.Address)["Street1"] == "54")) 
    Console.WriteLine(person.LastName + ", " + person.FirstName);

Answer 5

Based on your update, you can adapt Jared Par's code this way:

var result = collection.Where(x => x.Address.Contains("Street1=54"));
foreach ( var cur in result ) {
  Console.WriteLine(string.Format("{0}, {1}", cur.Name, cur.FullName));
}

If you want to be able to plug in your Street1 value with a variable, then do this:

var street1 = "54";
var result = collection.Where(x => x.Address.Contains("Street1=" + street1 ));
foreach ( var cur in result ) {
  Console.WriteLine(string.Format("{0}, {1}", cur.Name, cur.FullName));
}

BTW, you really should update your question or add a comment to a specific answer rather than adding a new answer that isn't.

Answer 6

So, what you could do is that you could write a generator for parsing the Address field and then enumerating properties of that. This is a fairly common thing in the functional programming world.

To be fair you would want this code to be lazy in that it would only compute a minimal set. I'm gonna suggest some code from the BCL but you can (and probably should) rewrite the same helper methods with generators.

public static IEnumerable<KeyValuePair<string,string>> NameValueSplit( this string s )
{
    foreach (var x in s.Split(','))
    {
        var y = x.Split(new char[] { '=' }, 2, StringSplitOptions.None);
        yield return new KeyValuePair<string, string>(y[0].TrimStart(), y[1].TrimEnd());
    }
}

With that helper function you can write code like this

var result = collection.Where(x => x.Address
    .NameValueSplit().Any(x => x.Key == "Street1" && x.Value == "54"));
foreach ( var item in result ) 
{
    Console.WriteLine(item.Name);
}

Now this code will not run on your SQL Server if you were thinking of that, but you could write a WHERE clause where you would search the Address field for a sub string %Street1=54%. I like lazy evaluation for string operations and think that's a lacking feature in the BCL. That is why I suggested that kind of solution.

Answer 7

No its not my List. It comes from somewhere.