I have a dictionary which has more than 2000+ elements. I am trying to update an element in the value based on a condition. How do I do that in a simple statement instead of looping through?
Dictionary<int, MyObj> testDictionary = new Dictionary<int, MyObj>();
testDictionary.Add(1,new MyObj() {Name = "John",Code = "JN",Id = null});
testDictionary.Add(2,new MyObj() {Name = "John",Code = "JN",Id = null});
testDictionary.Add(3,new MyObj() {Name = "Champ",Code = "CP",Id = null});
testDictionary.Add(4,new MyObj() {Name = "SMITH",Code = "SH",Id = null});
testDictionary.Add(5,new MyObj() {Name = "SMITH",Code = "SH",Id = null});
Dictionary<int, MyObj>
public class MyObj
{
public string Name { get; set; }
public string Code { get; set; }
public int? Id { get; set; }
}
How do I update all of Dictionary values (MyObj)
where Code = JN and Name = John with 100
where Code = SH and Name = SMITH with 989
I can get matched list using below statement but do I ressign to dictionary?
var enList = testDictionary.Values.Where(d => d.Name == "John" && d.Code == "JN");
Try the code bellow, this change the value of name to test attribute in any item where the value of Name is "SMITH".
testDictionary.Where(y => y.Value.Name == "SMITH")
.Select(r => r.Value)
.ToList<MyObj>()
.ForEach(k => k.Name = "test");
This line does not return result, the value is changed directly in the textDictionary instance.
Look at the example - you don't need to reassign values in the Dictionary, they are stored as references.
var enList = testDictionary.Values.Where(d => d.Name == "John" && d.Code == "JN").ToList();
foreach (var item in enList)
{
item.Name = "Updated Name";
}
Console.WriteLine(testDictionary[1].Name);
Related
I cannot seem to get the desirable filtered result from my query.
Data
public class fdp_1115
{
public string Id{ get; set; }
public string Number{ get; set; }
public string Type{ get; set; }
}
List<fdp_1115> fdpList = new List<fdp_1115>
{
new fdp_1115 { Id = "1", Number = "Lot123", Type = "D14MWT" },
new fdp_1115 { Id = "2", Number = "Lot123", Type = "E12WBC7W1" }
};
List<string> searchValues = new List<string> { "MLE12WBC7W1 A R" };
LINQ:
var LocType = fdpList.FirstOrDefault(d => searchValues.Any(s => d.Type.Contains(s)));
if (LocType != null)
{
Console.WriteLine("Matching record found:");
Console.WriteLine($"Id: {LocType.Id}, Number: {LocType.Number}, Type: {LocType.Type}");
}
else
{
Console.WriteLine("No matching records found.");
}
The result I wanted is:
Matching record found:
Id: 2, Number: Lot123, Type: E12WBC7W1
But I got "No matching records found." which indicates that LocType == null.
I already tried trimming and ignoring case sensitive:
var LocType = fdpList.FirstOrDefault(d => searchValues.Any(s => d.Type.Contains(s.Trim().Replace(" ", ""))));
var LocType = fdpList.FirstOrDefault(d => searchValues.Any(s => d.Type.Contains(s, StringComparison.InvariantCultureIgnoreCase)));
But still no luck. Any idea how do I match "MLE12WBC7W1 A R" with "E12WBC7W1"?
You have your contains the other way around.
d.Type = "E12WBC7W1"
and
s = "MLE12WBC7W1 A R"
Then "E12WBC7W1" does not Contains "MLE12WBC7W1 A R"
It is the other way around.
var LocType = fdpList.FirstOrDefault(d => searchValues.Any(s => s.Contains(d.Type)));
Your current logic checks whether there is any object with Type value that contains the value for each string in the searchValues array.
From your requirement:
You want to filter the object that fulfills there is any string in searchValues containing the value of Type.
Thus it should be:
var LocType = fdpList.FirstOrDefault(d => searchValues.Any(s => s.Contains(d.Type)));
I have IDictionary<int,bool?> where int - id, bool? - state (true,false,null)
So i need to filter ICollection of objects, where i should compare internal id with id of my IDictionary and if IDs are the same and the state is true - i should select this element (using LINQ)
I tried: incomeCollection.Values.Select(x=>x.InternalId.Equals(dataFromDictionary.Keys.Any)).Select(h=> new Item){Item = h.Name}
but it does not works. I need to check all collection and select elements, which satisfy the condition above using LINQ. How can i do this?
The dictionary has a handy TryGetValue method allowing to look up an entry quickly.
class Income
{
public int InternalId { get; set; }
public string Name { get; set; }
}
var dictionary = new Dictionary<int,bool?>
{
{1, false},
{2, true},
{3, null},
};
var incomeCollection = new List<Income>
{
new Income { InternalId = 1, Name = "A" },
new Income { InternalId = 2, Name = "B" },
new Income { InternalId = 3, Name = "C" },
new Income { InternalId = 4, Name = "D" },
};
var result = incomeCollection.Where(x =>
dictionary.TryGetValue(x.InternalId, out var status) && status == true)
.Select(h=> new {Item = h.Name});
This is better than your first approach using dataFromDictionary.Keys.Any which does not take advantage of the Dictionary feature of quick lookup.
You can use Any()
var result = list.Where(x=>dictionary.Keys.Any(c=>c.Equals(x.Id)) && x.State.HasValue && x.State==true).Select(x=>x);
You can also use Join.
var result = list.Join(dictionary,
l=>l.Id,
d=>d.Key,(l,d)=>l)
.Where(x=>x.State.HasValue && x.State==true).Select(x=>x);
For example,
var dictionary = new Dictionary<int,bool?>
{
[1] = true,
[3] = true,
[35] = false
};
var list = new List<Person>
{
new Person{Name="Jia", Id=1,State=false},
new Person{Name="Aami", Id=3,State=true},
new Person{Name="Anu", Id=35,State=null},
};
Output
Aami 3 True
ToDictionary method can be used as shown in the below example.
In order to select only few values from ICollection you can use where clause.
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2, TrackingNumber = 89453312L },
new Package { Company = "Lucerne Publishing", Weight = 18.7, TrackingNumber = 89112755L },
new Package { Company = "Wingtip Toys", Weight = 6.0, TrackingNumber = 299456122L },
new Package { Company = "Adventure Works", Weight = 33.8, TrackingNumber = 4665518773L } };
// Create a Dictionary of Package objects,
// using TrackingNumber as the key.
Dictionary<long, Package> dictionary =
packages.ToDictionary(p => p.TrackingNumber);
foreach (KeyValuePair<long, Package> kvp in dictionary)
{
Console.WriteLine(
"Key {0}: {1}, {2} pounds",
kvp.Key,
kvp.Value.Company,
kvp.Value.Weight);
}
I have two lists of same type with different key value pairs,
List1 has "isPermanent = true" and List2 has false value and also
List1 has an extra key "nextVacationDate".
Im trying to do union of these as below but im afraid I will still get the duplicates because of different values. I need to merge both lists in to one list and order by List1 first (Permanent employees first)..is there a better way to do this using LINQ?
public newList1 List1(string abcd)
{
var result = serviceMethod1(abcd);
var newList1 = new List<emp>();
if (result == null) return null;
newList.AddRange(
result.Select(x => new Model
{
firstName = x.FName,
secondName = x.SName,
address = x.Address,
employeeId = x.EmpId,
isPermanent = true,
nextVacationDate =x.VacDt,
salary = x.Bsalary
}));
return newList1;
}
public newList2 List2(string defg)
{
var result = serviceMethod2(defg);
var newList2 = new List<emp>();
if (result == null) return null;
newList.AddRange(
result.Select(x => new Model
{
firstName = x.FName,
secondName = x.SName,
address = x.Address,
employeeId = x.EmpId,
isPermanent = false,
salary = x.Bsalary
}));
return newList2;
}
private List<emp> EmployyeList(List<emp> newList1, List<emp> newList2)
{
var sortedEmpList1 = newList1.OrderBy(i => i.Fname);
var sortedEmpList2 = newList2.OrderBy(i => i.Fname);
List<MeterModel> combinedList = newList1.Union(newList2) as List<emp>;
return combinedList;
}
You can filter the 2nd list to avoid duplicates:
newList1.Union(newList2.Where(emp2 => !newList1.Any(emp1 => emp1.employeeId == emp2.employeeId)))
I am currently developing an application that requires this senario.
Assuming I have this object
public class ObjectItem
{
public int Id {get;set;}
public int Name {get;set;}
public int Sex {get;set;}
public int Age {get;set;}
public string Complexion {get;set;}
}
If we now have two lists of this object
var studentWithAge = new List<ObjectItem>
{
new ObjectItem {Id = 1, Name = "John", Age = 2},
new ObjectItem {Id = 2, Name = "Smith", Age = 5},
new ObjectItem {Id = 3, Name = "Juliet", Age = 7},
};
var studentWithSexAndComplexion = new List<ObjectItem>
{
new ObjectItem {Id = 1, Name = "John", Sex = "Male", Complexion = "fair"},
new ObjectItem {Id = 2, Name = "Smith", Sex = "Male", Complexion = " "},
new ObjectItem {Id = 3, Name = "Juliet", Sex = "Female", Complexion = "Blonde"},
new ObjectItem {Id = 4, Name = "Shittu", Sex = "Male", Complexion = "fair"},
};
I want to merge these two lists into just one. The end result should look like this.
var CompleteStudentData=new List<ObjectItem>
{
new ObjectItem{Id=1,Name="John",Sex="Male", Complexion="fair",Age=2},
new ObjectItem{Id=2,Name="Smith",Sex="Male", Complexion=" ", Age=5},
new ObjectItem{Id=3,Name="Juliet",Sex="Female", Complexion="Blonde", Age=7},
new ObjectItem{Id=4,Name="Shittu",Sex="Male", Complexion="fair", Age=0},
}
How do i achieve this? Using Union to merge the two list does not produce the desired result. I would appreciate your help.
var result = StudentWithAge.Join(StudentWithSexAndComplexion,
sa => sa.Id,
ssc => ssc.Id,
(sa, ssc) => new ObjectItem
{
Id = sa.Id,
Name = sa.Name,
Age = sa.Age,
Sex = ssc.Sex,
Complexion = ssc.Complexion
}).ToList();
Or, avoiding creation of new objects:
var result = StudentWithAge.Join(StudentWithSexAndComplexion,
sa => sa.Id,
ssc => ssc.Id,
(sa, ssc) =>
{
sa.Sex = ssc.Sex;
sa.Complexion = ssc.Complexion;
return sa;
}).ToList();
And if you want to add students presented only in the second list, than also:
result.AddRange(StudentWithSexAndComplexion.Where(ssc => !StudentWithAge.Any(sa => sa.Id == ssc.Id)));
Since it's possible that your collections will not have a 1-to-1 correspondence, you would have to do a full outer join. See here for how you can compose it that way.
Here's one way you can get similar results.
Collect all the keys (the ids) from both collections, then perform a left join with each of the collections, then combine the results.
var ids = studentWithAge.Select(s => s.Id)
.Union(studentWithSexAndComplexion.Select(s => s.Id));
var query =
from id in ids
from sa in studentWithAge
.Where(sa => sa.Id == id)
.DefaultIfEmpty(new ObjectItem { Id = id })
from ssc in studentWithSexAndComplexion
.Where(ssc => ssc.Id == id)
.DefaultIfEmpty(new ObjectItem { Id = id })
select new ObjectItem
{
Id = id,
Name = sa.Name ?? ssc.Name,
Sex = ssc.Sex,
Age = sa.Age,
Complexion = ssc.Complexion,
};
.Net has a function which is concatenating collections:
var concatenatedCollection = StudentWithAge.Concat(StudentWithSexAndComplexion).ToList();
var StudentWithAge = new List<ObjectItem>()
{
new ObjectItem{Id=1,Name="John",Age=2},
new ObjectItem{Id=2,Name="Smith",Age=5},
new ObjectItem{Id=3,Name="Juliet",Age=7},
};
var StudentWithSexAndComplexion = new List<ObjectItem>()
{
new ObjectItem{Id=1,Name="John",Sex="Male", Complexion="fair"},
new ObjectItem{Id=2,Name="Smith",Sex="Male", Complexion=" "},
new ObjectItem{Id=3,Name="Juliet",Sex="Female", Complexion="Blonde"},
new ObjectItem{Id=4,Name="Shittu",Sex="Male", Complexion="fair"},
};
var concatenatedCollection = StudentWithAge.Concat(StudentWithSexAndComplexion).ToList();
I am using Dynamic Linq helper for grouping data. My code is as follows :
Employee[] empList = new Employee[6];
empList[0] = new Employee() { Name = "CA", State = "A", Department = "xyz" };
empList[1] = new Employee() { Name = "ZP", State = "B", Department = "xyz" };
empList[2] = new Employee() { Name = "AC", State = "B", Department = "xyz" };
empList[3] = new Employee() { Name = "AA", State = "A", Department = "xyz" };
empList[4] = new Employee() { Name = "A2", State = "A", Department = "pqr" };
empList[5] = new Employee() { Name = "BA", State = "B", Department = "pqr" };
var empqueryable = empList.AsQueryable();
var dynamiclinqquery = DynamicQueryable.GroupBy(empqueryable, "new (State, Department)", "it");
How can I get back the Key and corresponding list of grouped items i.e IEnumerable of {Key, List} from dynamiclinqquery ?
I solved the problem by defining a selector that projects the Key as well as Employees List.
var eq = empqueryable.GroupBy("new (State, Department)", "it").Select("new(it.Key as Key, it as Employees)");
var keyEmplist = (from dynamic dat in eq select dat).ToList();
foreach (var group in keyEmplist)
{
var key = group.Key;
var elist = group.Employees;
foreach (var emp in elist)
{
}
}
The GroupBy method should still return something that implements IEnumerable<IGrouping<TKey, TElement>>.
While you might not be able to actually cast it (I'm assuming it's dynamic), you can certainly still make calls on it, like so:
foreach (var group in dynamiclinqquery)
{
// Print out the key.
Console.WriteLine("Key: {0}", group.Key);
// Write the items.
foreach (var item in group)
{
Console.WriteLine("Item: {0}", item);
}
}