I want to check the all items of the list2 exist in list1

Question

1.00/5 (2 votes)

See more:

C#

bool Issuboption = option.SubProductOptions.ToList().All(s => getsuboptions.ToList().All(p => p.Id == s.Id));

option.SubProductOptions-This is one list

getsuboptions -This is another list

Both are having same type of objects and same items in both list but while programmatically while checking using Id's with above stament. I got False bool value. Actually we will need True

if anything wrong please correct it.

Please help me

Thanks

What I have tried:

Both are having same type of objects and same items in both list but while programmatically while checking using Id's with above stament. I got False bool value. Actually we will get True

Posted 18-Nov-22 9:48am

Krishna Veni

Updated 18-Nov-22 10:31am

v3

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Graeme_Grant · Answer 1 · 2022-11-18T10:31:00

To determine if 2 lists are equal, you would use either SequenceEqual or Union.

Let me show you why:

C#

List<Item> itemsA = new();
List<Item> itemsB = new();

for (int i = 0; i < 10; i++)
{
    itemsA.Add(new Item(i, $"item {i}"));
}

itemsB = itemsA.OrderBy(x => Guid.NewGuid()).ToList();

// SequenceEqual method
Console.WriteLine("SequenceEqual method");

var AreEqual = Enumerable.SequenceEqual(itemsA.OrderBy(e => e.Id), itemsB.OrderBy(e => e.Id));
Console.WriteLine($"Are Equal = {AreEqual}");

itemsB.Add(new(11, "imposter"));

AreEqual = Enumerable.SequenceEqual(itemsA.OrderBy(e => e.Id), itemsB.OrderBy(e => e.Id));
Console.WriteLine($"Are Equal = {AreEqual}");

Console.WriteLine();

// Intersect method
Console.WriteLine("Intersect method");

itemsB = itemsA.OrderBy(x => Guid.NewGuid()).ToList();

int count = itemsA.Select(item => item.Id).Intersect(itemsB.Select(item => item.Id)).Count();
Console.WriteLine($"Are Equal = {count == itemsA.Count}");

itemsB.Add(new(11, "imposter"));

count = itemsA.Select(item => item.Id).Intersect(itemsB.Select(item => item.Id)).Count();
Console.WriteLine($"Are Equal = {count == itemsA.Count}");

Console.WriteLine();

// Union method
Console.WriteLine("Union method");

itemsB = itemsA.OrderBy(x => Guid.NewGuid()).ToList();

count = itemsA.Select(item => item.Id).Union(itemsB.Select(item => item.Id)).Count();
Console.WriteLine($"Are Equal = {count == itemsA.Count}");

itemsB.Add(new(11, "imposter"));

count = itemsA.Select(item => item.Id).Union(itemsB.Select(item => item.Id)).Count();
Console.WriteLine($"Are Equal = {count == itemsA.Count}");

Console.WriteLine();

// Except method
Console.WriteLine("Except method");

itemsB = itemsA.OrderBy(x => Guid.NewGuid()).ToList();

count = itemsA.Select(item => item.Id).Except(itemsB.Select(item => item.Id)).Count();
Console.WriteLine($"Are Equal = {count == 0}");

itemsB.Add(new(11, "imposter"));

count = itemsA.Select(item => item.Id).Except(itemsB.Select(item => item.Id)).Count();
Console.WriteLine($"Are Equal = {count == 0}");

// mock class
record Item(int Id, string Name);

And the output:

SequenceEqual method
Are Equal = True
Are Equal = False

Intersect method
Are Equal = True
Are Equal = True

Union method
Are Equal = True
Are Equal = False

Except method
Are Equal = True
Are Equal = True

For Intersect and Except, you need an additional check:

C#

itemsA.Count == itemsB.Count && count == itemsA.Count

UPDATE

As requested, the SequenceEqual as an extension method:

C#

// extension method
Console.WriteLine("extension method");

itemsB = itemsA.OrderBy(x => Guid.NewGuid()).ToList();

Console.WriteLine($"Are Equal = {itemsA.Eqaulity(itemsB)}");

itemsB.Add(new(11, "imposter"));

Console.WriteLine($"Are Equal = {itemsA.Eqaulity(itemsB)}");

public static class ItemCompareExtension
{
    public static bool Eqaulity(this List<Item> itemsA, List<Item> itemsB)
        => Enumerable.SequenceEqual(itemsA.OrderBy(e => e.Id), itemsB.OrderBy(e => e.Id));
}
// mock class
public record Item(int Id, string Name);

Output:

extension method
Are Equal = True
Are Equal = False

UPDATE #2

Comparing 2 different lists:

C#

List<Item> itemsA = new();
List<Item> itemsB = new();

for (int i = 0; i < 10; i++)
{
    itemsA.Add(new Item(i, $"item a {i}"));
}

for (int i = 0; i < 10; i++)
{
    itemsB.Add(new Item(i, $"item b {i}"));
}

Console.WriteLine("extension method");

itemsB = itemsA.OrderBy(x => Guid.NewGuid()).ToList();

Console.WriteLine($"Are Equal = {itemsA.Eqaulity(itemsB)}");

itemsB.Add(new(11, "imposter"));

Console.WriteLine($"Are Equal = {itemsA.Eqaulity(itemsB)}");

Output:

extension method
Are Equal = True
Are Equal = False

OriginalGriff · Answer 2 · 2022-11-18T10:24:00

Solution 1

All checks every element of the source - so if ListA is a superset of ListB then it will return false.

If you want to know if ListB is a subset of ListA, then I'd use Intersect instead: Enumerable.Intersect Method (System.Linq) | Microsoft Learn[^] with a custom IEquatable as shown in the examples.
If the intersection of the two collections has the same number of elements as the second collection, the first is a superset.

Posted 18-Nov-22 10:24am

OriginalGriff

Comments

Graeme_Grant 18-Nov-22 16:51pm

Both sets require an equal number of elements. if the second set has more, then the test will fail. You also need to compare the counts. Union is the better choice.

Krishna Veni 18-Nov-22 17:03pm

Union is combine all elements
But in this just determine how if two lists have equals items

Krishna Veni 18-Nov-22 17:00pm

Intersect common elements. I want if two lists have same number of items.