How to get difference between two array without using linq or Set operator using csharp ?

Question

I work on csharp
I have two arrays of string

A1 = [Watermelon, Apple, Mango, Guava, Banana]
A2 = [Orange, Kiwi, Apple, Watermelon]

i need to write code by csharp get difference between two arrays
and display difference between two arrays but without using linq or set operator

expected result

Answer 1

Hi, please refer the code below:

namespace MSTestProject    
{    
    [TestClass]    
    public class UnitTest1    
    {    
        [TestMethod]  
        public void Test()  
        {  
            var list = GetListDifference();  
            foreach (var item in list)    
            {    
                Console.WriteLine(item);    
            }    
        }  

        public List<string> GetListDifference()    
        {    
            var list1 = new List<string> { "Watermelon", "Apple", "Mango", "Guava", "Banana" };    
            var list2 = new List<string> { "Orange", "Kiwi", "Apple", "Watermelon" };    
    
            var elements = new List<string>();    
    
            foreach (var item1 in list1)    
            {    
                foreach (var item2 in list2)    
                {    
                    if (item1 == item2)    
                    {    
                        elements.Add(item1);    
                    }    
                }    
            }    
    
            if (elements.Count > 0)    
            {    
                foreach (var item in elements)    
                {    
                    list1.Remove(item);    
                    list2.Remove(item);    
                }    
            }    
    
            var result = new List<string>();    

            result.AddRange(list1);   
            result.AddRange(list2);   

            return result;  
        }    
    }    
}    

If right, please Accept.
Enjoy programming!!!

Answer 2

not sure why Banana was not included (where you supposed to only compare by min array size)

with banana

static string[] Diff(string[] list1, string[] list2)  
{  
	var diff = new List<string>();  
	foreach (var i in list1)  
	{  
		if (Array.IndexOf(list2, i) < 0) diff.Add(i);    
	}  
	foreach (var i in list2)  
	{  
		if (Array.IndexOf(list1, i) < 0) diff.Add(i);    
	}  
	return diff.ToArray();  
}  

without Banana

static string[] Diff(string[] list1, string[] list2)  
{  
	var diff = new List<string>();  
	var minSize = Math.Min(list1.Length, list2.Length);  
	  
	for (var i=0; i < minSize; ++i)  
	{  
		if (Array.IndexOf(list2, list1[i]) < 0) diff.Add(list1[i]);    
	}  
	for (var i=0; i < minSize; ++i)  
	{  
		if (Array.IndexOf(list1, list2[i]) < 0) diff.Add(list2[i]);    
	}  
  
	return diff.ToArray();  
}  
  

Answer 3

@ahmed salah , Welcome to Microsoft Q&A, you could refer to the following code to get difference between two array without using linq.

Code:

  static void Main(string[] args)  
        {  
            string[] arr1 = { "Watermelon", "Apple", "Mango", "Guava", "Banana" };  
            string[] arr2 = { "Orange", "Kiwi", "Apple", "Watermelon" };  
            List<string> result = new List<string>();  
            GetList(arr1, arr2, result);  
            GetList(arr2, arr1, result);  
            foreach (var item in result)  
            {  
                Console.WriteLine(item);  
            }  
            Console.WriteLine();  
        }  
        static void GetList(string[] arr1, string[] arr2,List<string> result)  
        {  
            foreach (string tmp in arr1)  
            {  
                bool existsInB = false;  
                foreach (string tmp2 in arr2)  
                {  
                    if (tmp == tmp2)  
                    {  
                        existsInB = true;  
                        break;  
                    }  
                }  
  
                if (!existsInB)  
                {  
                    result.Add(tmp);  
                }  
            }  
  
        }  

Result:

Hope the above code could help you.

Best Regards,
Jack

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