C-Sharp Logic Boolean Logic

The Simplest Way to Check If a Variable Equals a Value from a List in C#

When working with C#, it’s common to need to check if a variable matches one of several values. This question becomes, “what’s the most succinct way to accomplish this?” Particularly, you’ll want to avoid repeating the variable you’re checking against multiple times, while also steering clear of lengthy syntax implementations like arrays or lists when it’s unnecessary.

In this blog post, we will explore various solutions to determine if a variable is equal to one of a set of values efficiently using boolean logic.

The Common Approach

Often, developers might resort to using the logical OR operator (||) to perform a direct comparison like this:

int baseCase = 5;
bool testResult = baseCase == 3 || baseCase == 7 || baseCase == 12 || baseCase == 5;

While this solution works, it requires repetitive code for each value you need to check against. As you can see, if you have a long list of values, the code can quickly become cumbersome and prone to errors.

Rethinking Your Approach

One query raised was whether there’s a way to encapsulate this logic more succinctly without using long expressions or .NET 3.5 features. Most notably, you would like to avoid using constructs that require arrays. Let’s examine a more compact approach.

Using Contains

If you’re still interested in a more efficient way to check against multiple values, one of the best methods is leveraging the Contains method, albeit it does involve using an array or list. Here’s how you could write:

bool testResult = new int[] { 3, 7, 12, 5 }.Contains(baseCase);

Why Use Contains?

This method simplifies your code in several key ways:

  • Readability: It enhances code clarity. Anyone reading your code can instantly ascertain what you’re trying to do without deciphering an intricate OR operation.
  • Flexibility: You can quickly modify the list of values you’re checking against without changing your logic structure.
  • Scalability: Add or remove elements in your condition without concerns of code bloat or repetition.

Considerations for .NET 2.0 Users

Given the constraints of using the .NET 2.0 framework, some features available in later versions aren’t accessible. However, the Contains implementation shared above works well within .NET 2.0. The following remains a simple yet effective solution:

bool b = new int[] { 3, 7, 12, 5 }.Contains(5);

Conclusion

Determining if a variable is equal to any value from a set can be elegantly managed using the Contains method within an array. It offers a neat, compact solution while maintaining code readability and reducing the risk of error with lengthy logical expressions. Remember, as you build out more complex logic scenarios in C#, leveraging these methods can support clean, maintainable code that performs well even on older frameworks such as .NET 2.0.

So next time you need to check a variable against a list, keep these strategies in mind for cleaner code!