how to compare list of array and array

Question

2.00/5 (3 votes)

See more:

static List<int[,]> list = new List<int[,]>();
int[,] array={{1,1},{2,2}};
list.Add(array);

foreach(var element in list)
if(element==array)//return -1!!!!!! why?????
{
//
}

Posted 13-Jan-15 5:00am

Member 11253892

Add a Solution

Comments

CHill60 13-Jan-15 11:04am

Insufficient information - please update your question with an actual question

Sergey Alexandrovich Kryukov 13-Jan-15 11:10am

List of arrays and array are very different types, so, what is the comparison criteria?
(When you formulate them, you will already be close to the answer.)
—SA

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)

Sergey Kizyan · Answer 1 · 2015-01-13T05:18:00

Solution 1

You could use SequenceEqual. This works for any IEnumerable<t>, not just arrays

Posted 13-Jan-15 5:18am

Sergey Kizyan

Comments

Sergey Alexandrovich Kryukov 13-Jan-15 11:36am

Good idea, but only if the inquirer wants that; I would prefer to ask him first. List of arrays is two-level hierarchy, so maybe hierarchy should be flatten in certain way, or maybe he does not understand what he wants (also pretty likely), and so on.
Also, you should better provide a link.
—SA

BillWoodruff 13-Jan-15 20:18pm

There's a problem with SequenceEquals here because the OP is using two-dimensional Arrays; SequenceEquals will not work on multi-dimensional Arrays; there are ways to work around that, but they are kind of ugly. Example:

private string[] a1 = new[] {"1", "2", "3"};

private string[] a2 = new[] { "3", "4", "5" };

private string[] a3 = new[] { "1", "2", "3" };

private string[] a4 = new[] { "3", "4", "5" };

private List<string[]> a5;

private List<string[]> a6;

private void Test()
{
a5 = new List<string[]>{a1,a2};

a6 = new List<string[]>{a3,a4};

bool result1 = a5[0].SequenceEqual(a6[0]); // true

bool result2 = a5[1].SequenceEqual(a6[1]); // true

bool result3 = a5.SequenceEqual(a6); // false
}

BillWoodruff · Answer 2 · 2015-01-13T09:45:00

Your code will work as it is.

Do keep in mind that the reason it works is because you are comparing Value Types ... Ints ... not Reference Types !

here I am using the same comparison that you use, I've just packaged into a function:

C#

static List<int[,]> list = new List<int[,]>();
int[,] array={{1,1},{2,2}};

public bool isInArray(List<int[,]> list1, int[,] array)
{
    foreach (var subArray in list1)
    {
        if (subArray == array)
        {
            return true;
        }
    }

    return false;
}

// test in some method or EventHandler:

list.Add(array);

bool test = isInArray(list, array);