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Improve comparing between two collections - LINQ? C#

Edit:
_existingRatings and _targetRatings are both collections from a database, where Rating and RatingType are both key/values.
I've got two RatingDto collections that I need to compare each other against: _existingRates and _targetRates. I'll be simply doing a comparison on the RatingTypeId, then need to check if the same one in the _targetRates has an empty Rating string.
As it's Monday morning, my brain is still asleep and I'm sure there's a better and simpler way to do this with LINQ. This is what I'm currently doing:
class RatingDto
{
public int RatingTypeId { get; set; }
public string RatingType { get; set; }
public string Rating { get; set; }
}
foreach (var existing in _existingRatings)
{
foreach(var target in _targetRatings)
{
if(existing.RatingTypeId == target.RatingTypeId)
{
if(target.Rating == string.Empty)
{
_targetHasMissingRatings = true;
}
}
}
}
This should be okay as the maximum amount is around 7 in each collection, but I'm sure there's a better and cleaner way with LINQ.

That's should what you are looking for :
(i love to use string.IsNullOrEmpty rather than cmp string.Empty)
_targetHasMissingRatings = _existingRatings.Any(er => string.IsNullOrEmpty(_targetRatings.FirstOrDefault(tr => er.RatingTypeId == tr.RatingTypeId)?.Rating));

Use IComparable so you can use OrderBy on the entire class or simply compare two instances of the class.
List<RatingDto> ordered = _existingRatings.OrderBy(x => x).ToList();
See code below :
class RatingDto : IComparable<RatingDto>
{
public int RatingTypeId { get; set; }
public string RatingType { get; set; }
public string Rating { get; set; }
public int CompareTo(RatingDto other)
{
if (this.RatingTypeId != other.RatingTypeId)
{
return this.RatingTypeId.CompareTo(other.RatingTypeId);
}
else
{
return this.RatingType.CompareTo(other.RatingType);
}
}
}
Code would look like this :
List<RatingDto> _existingRatings = new List<RatingDto>();
List<RatingDto> _targetRatings = new List<RatingDto>();
Boolean _targetHasMissingRatings = false;
foreach (var existing in _existingRatings)
{
foreach (var target in _targetRatings)
{
if (existing == target)
{
_targetHasMissingRatings = true;
break;
}
}
if (_targetHasMissingRatings == true) break;
}

Get the values of dynamic keys from a JSON string

I have this json string and i want to get the 4th line (iValue, sValue) of every record.
My problem here is the keys vary for every record (based on the data type of the value).
Is there any way to do this on C#?
Here is an example:
{ "data": [
{
"pKey": "0",
"Entity": "tableName",
"Attribute": "CID",
"iValue": "13"
},
{
"pKey": "0",
"Entity": "tableName",
"Attribute": "username",
"sValue": "test_user1"
}] }

Here is kind of a big implementation, you will have to implement this for each iValue, fValue, etc however, it speeds up the implementation and usage. First of, here is the usage:
string rawJson = "{\"data\":[{\"pKey\":\"0\",\"Entity\":\"tableName\",\"Attribute\":\"CID\",\"iValue\":\"13\"},{\"pKey\":\"0\",\"Entity\":\"tableName\",\"Attribute\":\"username\",\"sValue\":\"test_user1\"}]}";
var values = JsonConvert.DeserializeObject<TakeData>(rawJson).Data.Select(v => v.PureData);
Now values contains the list. Here is the usage for accessing each:
foreach (var val in values)
{
if (val is IntData i)
{
int myInt = i.iValue;
// use the rest of the properties
}
else if (val is StrData s)
{
string myStr = s.sValue;
// use the rest of the properties
}
}
And here is the implementation:
class TakeData
{
public List<TakeItAll> Data { get; set; }
}
class TakeItAll
{
public int pKey { get; set; }
public string Entity { get; set; }
public string Attribute { get; set; }
private int _iValue;
public int iValue
{
get => _iValue;
set
{
_iValue = value;
PureData = new IntData { pKey = pKey, Entity = Entity, Attribute = Attribute, iValue = iValue };
}
}
private string _sValue;
public string sValue
{
get => _sValue;
set
{
_sValue = value;
PureData = new StrData { pKey = pKey, Entity = Entity, Attribute = Attribute, sValue = sValue };
}
}
public IPureData PureData { get; private set; }
}
interface IPureData
{
int pKey { get; set; }
string Entity { get; set; }
string Attribute { get; set; }
}
class IntData : IPureData
{
public int pKey { get; set; }
public string Entity { get; set; }
public string Attribute { get; set; }
public int iValue { get; set; }
}
class StrData : IPureData
{
public int pKey { get; set; }
public string Entity { get; set; }
public string Attribute { get; set; }
public string sValue { get; set; }
}
Of course you can use some alternatives as well. Such as using an enum in TakeItAll to keep track of the data type (or a type variable) instead of so many classes. This way However the size of the values object would be larger.
class TakeItAll
{
public int pKey { get; set; }
public string Entity { get; set; }
public string Attribute { get; set; }
private int _iValue;
public int iValue
{
get => _iValue;
set
{
_iValue = value;
ValType = typeof(string);
}
}
private string _sValue;
public string sValue
{
get => _sValue;
set
{
_sValue = value;
ValType = typeof(int);
}
}
public Type ValType { get; private set; }
}

I would deserialize this into an object supporting both types of properties and then by code try parsing either the integer or the string if the integer fails.
If the Attribute value gives you a clue as to which one to look for, you could also use that to prevent having to try parsing the integer every time.
I would not rely on the property being the "fourth" property every time, as I'm assuming this would be external data, where you may not be able to control whether these properties come out in the exact same order every time (now and in the future).

If you don't know the data type then you could use an object to handle it.
It's a good idea to deserialize JSON string to concrete class to avoid string manipulation mistake.
public class Datum
{
public object pKey { get; set; }
public string Entity { get; set; }
public string Attribute { get; set; }
public string iValue { get; set; }
public string sValue { get; set; }
}
public class DataCollection
{
public List<Datum> data { get; set; }
}
public void Test()
{
var str = "{\"data\":[{\"pKey\":\"0\",\"Entity\":\"tableName\",\"Attribute\":\"CID\",\"iValue\":\"13\"},{\"pKey\":\"0\",\"Entity\":\"tableName\",\"Attribute\":\"username\",\"sValue\":\"test_user1\"}]}";
var list = JsonConvert.DeserializeObject<DataCollection>(str);
var keys = list.data.Select(x => x.pKey).ToList();
}

Another option is to deserialize to dynamic and inspect that:
var json = "{\"data\":[{\"pKey\":\"0\",\"Entity\":\"tableName\",\"Attribute\":\"CID\",\"iValue\":\"13\"},{\"pKey\":\"0\",\"Entity\":\"tableName\",\"Attribute\":\"username\",\"sValue\":\"test_user1\"}]}";
var result = JsonConvert.DeserializeAnonymousType<dynamic>(json, null);
if (result.data != null)
{
for (var i = 0; i < result.data.Count; i++)
{
if (result.data[i]["iValue"] != null)
// Parse iValue
if (result.data[i]["sValue"] != null)
// Parse sValue
}
}

You could load the Json in a ExpandoObject
var expConverter = new ExpandoObjectConverter();
dynamic objList = JsonConvert.DeserializeObject<List<ExpandoObject>>(json, expConverter);
JSON array to ExpandoObject via JSON.NET
Then once you have loaded it in as a List<ExpandoObject> you may itterate over it as a dictionary.
foreach(var obj in objList)
{
//convert the object to a Dictionary and select the 4th element.
var yourresult = (obj as IDictionary<string, object>).ElementAt(3);
}

My two cents:
Get each object of the array as a KeyValuePair
var json = "your json here";
var root = JsonConvert.DeserializeObject<Root>(json);
foreach (var element in root.Data)
{
//===================================================> Here using object because your value type change. You can change it to string if your value is always wrapped in a string (like "13")
var keyValuePair = element.ToObject<Dictionary<string, object>>();
//here, for each object of the 'data' array, you can check if the desidered property exists
if (keyValuePair.ContainsKey("iValue"))
{
var propertyValue = keyValuePair["iValue"];
}
else if (keyValuePair.ContainsKey("sValue"))
{
var propertyValue = keyValuePair["sValue"];
}
// Or you can check the property name in the desidered position
if (keyValuePair.Keys.ElementAt(3) == "iValue")
{
var propertyValue = keyValuePair["iValue"];
}
else if (keyValuePair.Keys.ElementAt(3) == "sValue")
{
var propertyValue = keyValuePair["sValue"];
}
}
Where Root is
class Root
{
[JsonProperty("data")]
public List<JObject> Data { get; set; }
}
With this solution you can always know which property (iValue or sValue) is specified. On the contrary, if you use a model class which has both property names, you wouldn't know which property is specified when the value is null (unless you use additional properties/classes and a custom JsonConverter).
Edit
As Panagiotis Kanavos reminded me, the JObject class implements IDictionary<string, JToken>. So, inside your foreach you could use:
if (element["iValue"] != null)
{
var propertyValue = element["iValue"].Value<string>();
}
if (element["sValue"] != null)
{
var propertyValue = element["sValue"].Value<string>();
}
// Or you can check the property name in the desidered position
var propName = element.Properties().ElementAt(3).Name;
if (propName == "iValue")
{
var propertyValue = keyValuePair["iValue"].Value<string>();
}
else if (propName == "sValue")
{
var propertyValue = keyValuePair["sValue"].Value<string>();
}
Of course you can optimize this code and check for nulls.

Remove the null property from object

,I have one class in which I have three properties now what I want to do, if in the object if any one of null or empty then I want to remove it from the object below is my code.
public class TestClass
{
public string Name { get; set; }
public int ID { get; set; }
public DateTime? DateTime { get; set; }
public string Address { get; set; }
}
TestClass t=new TestClass();
t.Address="address";
t.ID=132;
t.Name=string.Empty;
t.DateTime=null;
Now here I want the object of TestClass but in that Name and DateTime property should not be their in the object,
is it possible?
Please help me

There's no such concept as removing a property from an individual object. The type decided which properties are present - not individual objects.
In particular, it will always be valid to have a method like this:
public void ShowDateTime(TestClass t)
{
Console.WriteLine(t.DateTme);
}
That code has no way of knowing whether you've wanted to "remove" the DateTime property from the object that t refers to. If the value is null, it will just get that value - that's fine. But you can't remove the property itself.
If you're listing the properties of an object somewhere, you should do the filtering there, instead.
EDIT: Okay, no you've given us some context:
ok I am using Schemaless database so null and empty value also store space in database that's the reason
So in the code you're using which populates that database, just don't set any fields which corresponds to properties with a null value. That's purely a database population concern - not a matter for the object itself.
(I'd also argue that you should consider how much space you'll really save by doing this. Do you really care that much?)

I was bored and got this in LINQPad
void Main()
{
TestClass t=new TestClass();
t.Address="address";
t.ID=132;
t.Name=string.Empty;
t.DateTime=null;
t.Dump();
var ret = t.FixMeUp();
((object)ret).Dump();
}
public static class ReClasser
{
public static dynamic FixMeUp<T>(this T fixMe)
{
var t = fixMe.GetType();
var returnClass = new ExpandoObject() as IDictionary<string, object>;
foreach(var pr in t.GetProperties())
{
var val = pr.GetValue(fixMe);
if(val is string && string.IsNullOrWhiteSpace(val.ToString()))
{
}
else if(val == null)
{
}
else
{
returnClass.Add(pr.Name, val);
}
}
return returnClass;
}
}
public class TestClass
{
public string Name { get; set; }
public int ID { get; set; }
public DateTime? DateTime { get; set; }
public string Address { get; set; }
}

Hereby a 'slightly' more clear and shorter version of the accepted answer.
/// <returns>A dynamic object with only the filled properties of an object</returns>
public static object ConvertToObjectWithoutPropertiesWithNullValues<T>(this T objectToTransform)
{
var type = objectToTransform.GetType();
var returnClass = new ExpandoObject() as IDictionary<string, object>;
foreach (var propertyInfo in type.GetProperties())
{
var value = propertyInfo.GetValue(objectToTransform);
var valueIsNotAString = !(value is string && !string.IsNullOrWhiteSpace(value.ToString()));
if (valueIsNotAString && value != null)
{
returnClass.Add(propertyInfo.Name, value);
}
}
return returnClass;
}

You could take advantage of the dynamic type:
class Program
{
static void Main(string[] args)
{
List<dynamic> list = new List<dynamic>();
dynamic
t1 = new ExpandoObject(),
t2 = new ExpandoObject();
t1.Address = "address1";
t1.ID = 132;
t2.Address = "address2";
t2.ID = 133;
t2.Name = "someName";
t2.DateTime = DateTime.Now;
list.AddRange(new[] { t1, t2 });
// later in your code
list.Select((obj, index) =>
new { index, obj }).ToList().ForEach(item =>
{
Console.WriteLine("Object #{0}", item.index);
((IDictionary<string, object>)item.obj).ToList()
.ForEach(i =>
{
Console.WriteLine("Property: {0} Value: {1}",
i.Key, i.Value);
});
Console.WriteLine();
});
// or maybe generate JSON
var s = JsonSerializer.Create();
var sb=new StringBuilder();
var w=new StringWriter(sb);
var items = list.Select(item =>
{
sb.Clear();
s.Serialize(w, item);
return sb.ToString();
});
items.ToList().ForEach(json =>
{
Console.WriteLine(json);
});
}
}

May be interfaces will be handy:
public interface IAdressAndId
{
int ID { get; set; }
string Address { get; set; }
}
public interface INameAndDate
{
string Name { get; set; }
DateTime? DateTime { get; set; }
}
public class TestClass : IAdressAndId, INameAndDate
{
public string Name { get; set; }
public int ID { get; set; }
public DateTime? DateTime { get; set; }
public string Address { get; set; }
}
Creating object:
IAdressAndId t = new TestClass()
{
Address = "address",
ID = 132,
Name = string.Empty,
DateTime = null
};
Also u can put your interfaces in separate namespace and make your class declaration as internal. After that create some public factories which will create the instances of your classes.

ordering generic list by size property

Hi I have had to use interfaces before but ive been told i need to implement icomparable in this instance. see below:
internal class doorItem : IComparable
{
public int CompareTo(doorItem other)
{
// The temperature comparison depends on the comparison of the
// the underlying Double values. Because the CompareTo method is
// strongly typed, it is not necessary to test for the correct
// object type.
return GetNumber(productSize).CompareTo(GetNumber(other.productSize));
}
public string variations { get; set; }
public double pricerange { get; set; }
public string viewDetailsLink { get; set; }
public string height { get; set; }
public string width { get; set; }
public string productSize { get; set; }
public string productImage { get; set; }
public int countItemsOnSale { get; set; }
public string optionFor35Product { get; set; }
private int GetNumber(string str)
{
//this method gets the int out of the string
int length = str.Length;
string output = String.Empty;
int test = 0;
bool err = false;
for (int i = 0; i <= length; i++)
{
try
{
test = Convert.ToInt32(str.Substring(i, 1));
}
catch
{
err = true;
}
if (!err)
output += str.Substring(i, 1);
else
break;
}
return Convert.ToInt32(output);
}
}
above is the class i have created, door sizes are returned like this: 4dr, 5dr, 6dr etc.. then the getnumber method gets the int out of the string.
i have a generic list in of my custom class in the main method like this:
List<doorItem> d = new List<doorItem>();
i cant work out how to order this list by door size.... PLEASE HELP

It's easiest to do this using LINQ. Then you don't even need to implement IComparable.
var sortedList = doorList.OrderBy( d => d.GetNumber(d.productSize ).ToList();
And make GetNumber public inside the doorItem class.

I don't know if performance is important, but that method for getting the number is pretty horrible, exceptions should only be used in exceptional circumstances! Suggest something like this
StringBuilder sb = new StringBuilder();
foreach (char c in str)
{
if (Char.IsNumber(c))
{
sb.append(c);
}
}
return Convert.ToInt32(sb.ToString());
For sorting you can do what stecya has suggested, or you could convert this method to a property and sort directly.
public int Size
{
get
{
return GetNumber(this.productSize);
}
}
...
d.OrderBy(x=>x.Size);

Comparing Object properties using reflection

I have two classes Address and Employee as follows:
public class Address
{
public string AddressLine1 { get; set; }
public string AddressLine2 { get; set; }
public string City { get; set; }
public string State { get; set; }
public string Zip { get; set; }
}
public class Employee
{
public string FirstName { get; set; }
public string MiddleName { get; set; }
public string LastName { get; set; }
public Address EmployeeAddress { get; set; }
}
I have two employee instances as follows:
var emp1Address = new Address();
emp1Address.AddressLine1 = "Microsoft Corporation";
emp1Address.AddressLine2 = "One Microsoft Way";
emp1Address.City = "Redmond";
emp1Address.State = "WA";
emp1Address.Zip = "98052-6399";
var emp1 = new Employee();
emp1.FirstName = "Bill";
emp1.LastName = "Gates";
emp1.EmployeeAddress = emp1Address;
var emp2Address = new Address();
emp2Address.AddressLine1 = "Gates Foundation";
emp2Address.AddressLine2 = "One Microsoft Way";
emp2Address.City = "Redmond";
emp2Address.State = "WA";
emp2Address.Zip = "98052-6399";
var emp2 = new Employee();
emp2.FirstName = "Melinda";
emp2.LastName = "Gates";
emp2.EmployeeAddress = emp2Address;
Now how can I write a method which compares these two employees and returns the list of properties which have different values. So in this example I would like the result to be FirstName and Address.AddressLine1 .

Like LBushskin said, you do not have to do this. This is not the fastest way! Buy if you want, try this:
public static List<PropertyInfo> GetDifferences(Employee test1, Employee test2)
{
List<PropertyInfo> differences = new List<PropertyInfo>();
foreach (PropertyInfo property in test1.GetType().GetProperties())
{
object value1 = property.GetValue(test1, null);
object value2 = property.GetValue(test2, null);
if (!value1.Equals(value2))
{
differences.Add(property);
}
}
return differences;
}

You don't necessarily need reflection to perform the comparison. You can write a comparer class that takes two instances of Employee or Address, and compares each field that should match. For any that don't match, you can add a string (or PropertyInfo) element to some list to return to the caller.
Whether you return a PropertyInfo, MemberInfo, or just a string depends on what the caller needs to do with the result. If you actually need to visit the fields that contain differences, the PropertyInfo/MemberInfo may be better - but to just report the differences a string is probaby sufficient.
The main value of reflection would be to write a general purpose object comparer that could take two instances of any kind of object and compare their public fields and properties. This helps avoid writing repetetive comparison code over and over - but that doesn't seem like the case you're in.

Here is a generic and recursive solution based on Oskar Kjellin's awnser.
I have posted this code as gist as well, so you can check the latest version or star/clone/fork it :)
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
protected List<KeyValuePair<Type, PropertyInfo>> RecrusiveReflectionCompare<T>(T first, T second)
where T : class
{
var differences = new List<KeyValuePair<Type, PropertyInfo>>();
var parentType = first.GetType();
void CompareObject(object obj1, object obj2, PropertyInfo info)
{
if (!obj1.Equals(obj2))
{
differences.Add(new KeyValuePair<Type, PropertyInfo>(parentType, info));
}
}
foreach (PropertyInfo property in parentType.GetProperties())
{
object value1 = property.GetValue(first, null);
object value2 = property.GetValue(second, null);
if (property.PropertyType == typeof(string))
{
if (string.IsNullOrEmpty(value1 as string) != string.IsNullOrEmpty(value2 as string))
{
CompareObject(value1, value2, property);
}
}
else if (property.PropertyType.IsPrimitive)
{
CompareObject(value1, value2, property);
}
else
{
if (value1 == null && value2 == null)
{
continue;
}
differences.Concat(RecrusiveReflectionCompare(value1, value2));
}
}
return differences;
}

public IEnumerable<PropertyInfo> GetNotEqualsProperties(Employee emp1, Employee emp2)
{
Type employeeType = typeof (Employee);
var properies = employeeType.GetProperties();
foreach (var property in properies)
if(!property.GetValue(emp1, null).Equals(property.GetValue(emp2, null))) //TODO: check for null
yield return property;
}
And for complex properties you have to override Equals method
public class Address
{
public string AddressLine1 { get; set; }
public string AddressLine2 { get; set; }
public string City { get; set; }
public string State { get; set; }
public string Zip { get; set; }
public override bool Equals(object obj)
{
if (obj as Address == null)
return false;
return ((Address) obj).AddressLine1.Equals(AddressLine1);
}
}

No need for reflection. Of course, this example is returning a string with the property names...if you need the actual PropertyInfo object, things would get a little more difficult, but not by much.
public static IEnumerable<string> DiffEmployees
(Employee one, Employee two)
{
if(one.FirstName != two.FirstName)
yield return "FirstName";
if(one.LastName != two.LastName)
yield return "LastName";
if(one.Address.AddressLine1 != two.Address.AddressLine1)
yield return "Address.AddressLine1";
// And so on.
}