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Indexes that correspond to each other in two Lists

I have two Lists:
List<string> names = new List<string>();
List<int> goals = new List<int>();
One of them is a string List while the other one is a int List. I add some numbers in the second List, and then I get the biggest number in the List. This works.
Now I need to type some names in the console and after each name I need to type a certain number and this repeats to whenever I want.
How do I get the index of the biggest number in the second list and to print it alongside the name that actually have "scored" that biggest number? I want to get the index from the first string List that corresponds to the index of the biggest number in the second List. Is there a way that I can do it?

In your case, "Name" and "Goals" relate to each other. Someone or something with a "Name" has obviously attached to them a number of "Goals". So, let's reflect this relation in a class:
public class StatisticsItem
{
// Properties here
public string Name {get; set;}
public int Goals {get; set;}
}
You then can create new instances of that class like so:
var item = new StatisticsItem() { Name = "Marc", Goals = 5 };
and you can put those in a list:
var myList = new List<StatisticsItem>();
myList.Add(item);
Find your champion:
using System.Linq;
// ...
Console.WriteLine("Goalie King: {0}", myList.MaxBy(x => x.Goals).Name);
See in action: https://dotnetfiddle.net/I9w5u7
To be a bit more clean, you could of course use a constructor:
public class StatisticsItem
{
// Properties here
public string Name {get; set;}
public int Goals {get; set;}
public StatisticsItem(string name, int goals)
{
Name = name;
Goals = goals
}
}
// and then create instances like so:
var item = new StatisticsItem("Marc", 5);

Can't comment so i will add my opinion here. Fildor suggested 1 list with 2 properties which should cover your case. I would say also check if a dictionary<string, int> or a dictionary<string, List<int>> is a better fit instead of a list.
Keep in mind for a dictionary to work the key (name in your case) must be unique. If not discard this answer

Except in LINQ C#

I have to lists. One that contains all the valid chapter codes(chpt_cd) and their associated appl src codes. i.e the list is
List<ChapterCodeValidationOutput>
The base model class is
public class ChapterCodeValidationOutput
{
public string chpt_cd { get; set; }
public string appl_src_cd { get; set; }
}
The list sample data is ..
chpt_cd aapl_src_cd
------- -----------
07038 C062
07038 C062
06206 C191
And another list contains invalid chapter codes only.
List<string>
only.
And it's sample data is '06206'
I have to find the associated appl_src_cd of the invalid chapter codes list i.e. 'C191' and so on . The returned should be a list only.

Except will not help you in this case.
Assuming that these are the lists:
List<ChapterCodeValidationOutput> list1 = ...
List<string> list2 = ...
Then you can create a lookup from the first list for fast lookup like this:
var lookup = list1.ToLookup(x => x.chpt_cd, x => x.appl_src_cd);
And then use it like this to get the list of corresponding codes:
var result = list2.Select(x => lookup[x].First()).ToList();
I am assuming (since you mentioned in the comments), that if there are duplicate chpt_cd values, the corresponding appl_src_cd values will be equal.

Usage of Dictionaries in C#

I'm an old, old programmer so I'm very used to abuse Arrays but I will need to start using dictionaries since they can dynamically expand and Arrays can't.
Now... I need to populate values for a solar system where each body in that solar system have perhaps about 20-30 different values.
My intention was to use a dictionary where each body has it's own unique Key and a value, such as...
Dictionary<int,string> BodyName = new Dictionary<int,string>()
Dictionary<int,int> BodySize = new Dictionary<int,int>()
Dictionary<int,int> BodyX = new Dictionary<int,int>()
Dictionary<int,int> BodyY = new Dictionary<int,int>()
Dictionary<int,int> BodyVelocity = new Dictionary<int,int>()
etc...
my question is what's the best way to go about to retrieve the values from all these dictionaries?
The key for each 'body" is the same in each dictionary. I know I can do this with lots of loops, but that seems quite wasteful on CPU cycles and that is a bad thing for me.
I also considered Dictionary,List but that has other issues I don't particularly like.

Create a composite type, and use that.
Sticking with Dictionaries is suitable if the key is a unique identifier - a planet ID? a planet name? - that must be used to look up the data. Don't forget that iteration over dictionaries is non-deterministic.
Dictionary<int,PlanetaryBody> Bodies = new Dictionary<int,PlanetaryBody>()
On the other hand, a sequence is suitable if the planets are only iterated (or accessed by positional indices). In this case, using a List often works well.
List<PlanetaryBody> Bodies = new List<PlanetaryBody>();
// Unlike arrays, Lists grows automatically! :D
Bodies.Add(new PlanetaryBody { .. });
(I very seldom choose an array over a List - it's better sometimes, but not often.)
The composite type (i.e. class) is used to group the different attributes into a larger concept or classification group:
class PlanetaryBody {
public string Name { get; set; }
public double Mass { get; set; }
// etc.
}

Just use a class for that.
public class Planet {
public int Id { get; set; }
public string Name { get; set; }
public int Size { get; set; }
// and so on for each property of whatever type you need.
}
When you need a new Planet just new up:
var planet = new Planet();
planet.Name = "Saturn";
// again finish populating the properties.
To add it to a list:
var list = new List<Planet>();
list.Add(planet);
// adding the planet you created above.
Then look into manipulating lists and so on using LINQ

What I should use to store a list of assosiated values to be able to retrieve, modify and save one of the elements

I am new to C# and I do not know how to do this
I have a set of associated values
dateValue (string)
valueOne (decimal)
valueTwo (decimal)
I need to be able to pick up the values by a certain date (I could change the dateValue to datetime) and save all the values after modify the valueOne and valueTwo
Should I create a list of objects and loop all the list searching for the proper dateValue which valueOne and valueTwo I want to modify?
What will be the best solution
Create a class, instantiate all the values and then add them to a list?
How could I search for an specific date?

It sounds like a Dictionary may be what you are looking for. A dictionary is a means of storing a Key/value pair and allowing fast and easy lookup of items by key. The key will be dateValue. The Value of the dictionary might be a class that contains valueOne and valueTwo. For example:
var dictionary = new Dictionary<string, Values>();
//Add an item to the dictionary
dictionary.Add("thekey", new Values {ValueOne = 1, ValueTwo = 2});
//Get the item out of the dictionary by key
var values = dictionary["thekey"];
//Update the value of ValueOne for "thekey"
values.ValueOne = 7;
//Print the new value
Console.WriteLine(dictionary["thekey"].ValueOne);
And the class:
public class Values
{
public decimal ValueOne { get; set; }
public decimal ValueTwo { get; set; }
}
As an aside, why not storedateValue as a DateTime rather than a string? This allows you to to have access to various APIs for working with date and time, such as formatting it for display, arithmetic, etc.

In object-oriented programming, you should represent your associated values with a class:
public class MyAssociatedValues // come up with a better name
{
public DateTime Date{get;set;}
public decimal Value1{get;set;} // needs a better name
public decimal Value2{get;set;} // ditto
}
Once you are representing your collection as an IEnumerable<MyAssociatedValues> (this could be a List, an array, or a number of other structures that implement IEnumerable<>), you can easily create a Dictionary to key these values based on their date.
var valuesByDate = values.ToDictionary(v => v.Date);

For easy retrieval by dateValue you could either use a Dictionary with a Tuple containing the two values
Dictionary<string, Tuple<string, string>>
or a Lookup, which is basically a Dictionary that can store a collection of values per key.

I would use a Dictionary to map the DateTime to a structure that contains valueOne and valueTwo.
Something like:
struct Data
{
public decimal valueOne { get; set; }
public decimal valueTwo { get; set; }
}
Dictionary<DateTime, Data> map = new Dictionary<DateTime, Data>();
void addToMap(DateTime dt, decimal one, decimal two)
{
map[dt] = new Data() { valueOne = one, valueTwo = two };
}

Firstly, I would create a class (POCO) instead of a struct unless you have a good reason for a struct.
public class TheClass
{
public DateTime TheDate { get; set; }
public decimal ValueOne { get; set; }
public decimal ValueTwo { get; set; }
}
Secondly, I would store them in any data structure that implements IEnumerable (collection-type) that makes sense. The one that doesn't seem to make sense to me is the one that everyone is suggesting (Dictionary) because it is very much possible that you have 2 objects with the same datetime, so why everyone is suggesting a dictionary baffles me. The only thing I can think of is that they are assuming you only have one pair of values per datetime.
Thirdly, use LINQ to enumerate over the sub-list based on your query.
foreach (var obj in myCollection.Where(item => item.TheDate == requestedDate))
{
//Do whatever you need to do to each enumerated item.
}
Alternatively, if you really want to use the Dictionary instead of LINQ you could create an IDictionary<DateTime, IEnumerable<TheClass>> which means you are caching the collection as the value in the Dictionary.
foreach (var obj in myDictionary[requestedDate])
{
//Do whatever you need to do to each enumerated item.
}

Binding a Dictionary to the DataGridView in C#?

I have a dictionary item as below
Dictionary<string, List<StrikePrice>>
where
public class StrikePrice
{
public string Strike { get; private set; }
public string Price { get; private set; }
public StrikePrice(string strike, string price)
{
Strike = strike;
Price = price;
}
}
and I wish to assign this dictionary to the DataGridView
this.dataGridViewTest.DataSource = listSmiles;
I understand that a dictionary can't be assigned to the the DataSource as this doesn't derive from the IList interface.
Is there any way I can assign this dictionary element to the datagrid?

I know this is a bit old, but perhaps it will help someone. This one line solution worked for me
gridTAV.DataSource = dTAV.Values.ToList<TotalAccountValue>();
gridTAV is a DataGridView. dTAV is a Dictionary. The key is a date (not important), and the value is a class.
Dictionary<DateTime, TotalAccountValue> dTAV = new Dictionary<DateTime, TotalAccountValue>();
Since the value was a class the "ToArray()" method did not work for me, since it didn't "unpack" the class properties.
Note that this does not place the KEY in the grid, but I didn't really need that.

Yes ,by Calling ToArray of Dictionary
var g = this.dataGridView1;
var s = new Dictionary<string, string>();
s.Add("1", "Test1");
s.Add("2", "Test2");
s.Add("3", "Test3");
g.DataSource = s.ToArray();

Have you tried using the Values property of the Dictionary?
this.dataGridViewTest.DataSource = listSmiles.Values.ToList();

If the question relates to WPF or silverlight, this article gives a solution.
I've been using it and it performs well, even for large numbers of columns.