How to Check if a String Array Contains a Specific Element in C#?

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Check if a String Array Contains a Specific Element in C#

In this C# tutorial, I will show you, how to check if a string array contains a specific element in C# with a complete example.

When you’re working with arrays in C#, you might need to determine whether an array contains a particular element. In C#, the System.Array class does not have a built-in Contains method for checking the existence of an element, but the System.Linq namespace provides an extension method that allows you to easily accomplish this task.

In this tutorial, I will explore how to use the Contains() method to check if a string array contains a specific element in C#.

Check if a String Array Contains a Specific Element in C#

We can use the Contains() method to check if a string array contains a specific element in the C# array.

To use the Contains in C# method, you’ll need to include the System.Linq namespace in your code. Here’s how you can do it:

using System;
using System.Linq;  // Required for the Contains method

namespace StringArrayContains
{
    class Program
    {
        static void Main(string[] args)
        {
            // Initialize a string array with some names
            string[] names = { "John", "Alice", "Bob", "Emily", "Sophia" };

            // Check if the array contains the name "John"
            bool containsJohn = names.Contains("John");
            Console.WriteLine($"Array contains 'John': {containsJohn}");  // Output: Array contains 'John': True

            // Check if the array contains the name "Michael"
            bool containsMichael = names.Contains("Michael");
            Console.WriteLine($"Array contains 'Michael': {containsMichael}");  // Output: Array contains 'Michael': False

            // Check if the array contains any name from another array
            string[] usaNames = { "George", "Thomas", "James" };
            bool containsAnyUsaName = names.Intersect(usaNames).Any();
            Console.WriteLine($"Array contains any name from the list of USA names: {containsAnyUsaName}");  // Output: Array contains any name from the list of USA names: False
        }
    }
}

In this example, we define a string array named names and populate it with some example names. Then we use the Contains method from the System.Linq namespace to check if “John” and “Michael” are present in the array.

You can also see the output below:

Check if a String Array Contains a Specific Element in C#

Alternatives to Using Contains

If you do not want to use the System.Linq namespace for some reason, there are other ways to accomplish the same thing. You can use a foreach loop or the Array.Exists method.

Using foreach Loop

We can also use foreach loop to check if a string array contains a specific element in C#.

bool containsJohn = false;
foreach (string name in names)
{
    if (name == "John")
    {
        containsJohn = true;
        break;
    }
}

Using Array.Exists Method

We can also use the using Array.Exists() method to check if a string array contains a specific element in C#.

bool containsJohn = Array.Exists(names, element => element == "John");

Remember that the Contains method is case-sensitive. If you want a case-insensitive search, you can convert the array and the search term to lower or upper case before performing the check:

bool containsJohnCaseInsensitive = names.Select(name => name.ToLower()).Contains("john".ToLower());

Conclusion

The Contains method provided by the System.Linq namespace offers a convenient way to check if a string array contains a specific element. While you can achieve the same result with loops or Array.Exists, using Contains makes your code cleaner and easier to understand. I hope you got an idea of how to check if a string array contains a specific element in C#.

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