How to Compare Two Strings Character by Character in C#?

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how to compare two strings character by character in c#

In this C# tutorial explains, how to compare two strings character by character in C# using various methods and examples.

Compare Two Strings Character by Character in C#

Let us check out, how to compare two strings character by character in C# using various methods.

Method 1: Using For Loop

The most straightforward way to compare two strings character by character is by using a for loop in C#. First, check if both strings have the same length. If they do, you can proceed to compare each character one by one.

Here’s how you can do it:

using System;

namespace StringComparisonExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string name1 = "Alice";
            string name2 = "Alicia";

            if (name1.Length != name2.Length)
            {
                Console.WriteLine("The strings have different lengths, hence they are not equal.");
            }
            else
            {
                bool areEqual = true;

                for (int i = 0; i < name1.Length; i++)
                {
                    if (name1[i] != name2[i])
                    {
                        areEqual = false;
                        Console.WriteLine($"Strings differ at character {i + 1}: {name1[i]} != {name2[i]}");
                        break;
                    }
                }

                if (areEqual)
                {
                    Console.WriteLine("The strings are equal.");
                }
            }
        }
    }
}

In this example, the names “Alice” and “Alicia” are compared. Since their lengths are different, the program outputs that they are not equal. You can check out the output like the below screenshot.

compare two strings character by character in c#

Method 2: Using foreach and IEnumerator

Another way to compare two strings is by using foreach along with IEnumerator in C#. This method works well if you want to compare strings without caring about their length differences.

Here’s how you can do it:

using System;
using System.Collections.Generic;

namespace StringComparisonExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string name1 = "John";
            string name2 = "Johnny";

            IEnumerator<char> enumerator1 = name1.GetEnumerator();
            IEnumerator<char> enumerator2 = name2.GetEnumerator();

            int position = 0;
            while (enumerator1.MoveNext() && enumerator2.MoveNext())
            {
                if (enumerator1.Current != enumerator2.Current)
                {
                    Console.WriteLine($"Strings differ at character {position + 1}: {enumerator1.Current} != {enumerator2.Current}");
                    return;
                }
                position++;
            }

            if (enumerator1.MoveNext() || enumerator2.MoveNext())
            {
                Console.WriteLine("The strings have different lengths, hence they are not equal.");
            }
            else
            {
                Console.WriteLine("The strings are equal.");
            }
        }
    }
}

Method 3: Using LINQ

If you’re comfortable with LINQ, you can use it to compare two strings elegantly. This method is concise but might not be as straightforward as the previous ones.

using System;
using System.Linq;

namespace StringComparisonExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string name1 = "Emily";
            string name2 = "Emma";

            bool areEqual = name1.Length == name2.Length &&
                            !name1.Where((t, i) => t != name2[i]).Any();

            if (areEqual)
            {
                Console.WriteLine("The strings are equal.");
            }
            else
            {
                Console.WriteLine("The strings are not equal.");
            }
        }
    }
}

In this example, names “Emily” and “Emma” are compared. They are found to be unequal as their lengths are different and their characters don’t match entirely. You can see the output like below in the screenshot.

how to compare two strings character by character in c#

Conclusion

There are multiple ways to compare strings character by character in C#. In this tutorial, we checked 3 methods to compare strings character by character in C#.

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