In this article, we’re going to talk about the StringBuilder class, and explore options to check if it is empty, directly or indirectly.
So, let’s start.
What Is a StringBuilder Class?
StringBuilder is a string-like object whose value is a mutable sequence of characters. It is a class designed to make string manipulation as easy and as fast as possible.Â
It is recommended to use this class when we make heavy use of string concatenation, appending, inserting, removing, etc. String manipulation is expensive if we use String
class thanks to how the String
class operates in the .NET framework.
Let’s say that we decided to use the StringBuilder
class and want to check if a StringBuilder
object is empty.
We can do this in two ways, directly or indirectly.
Check if StringBuilder Is Empty Using the Length Property
The StringBuilder
class has a property named Length
that shows how many Char
objects it holds.
So, let’s use the LengthÂ
property:
var filledStringBuilder = new StringBuilder("example string value"); if(filledStringBuilder.Length == 0) { Console.WriteLine("StringBuilder is empty!"); } else { Console.WriteLine($"StringBuilder is not empty and lenght is {filledStringBuilder.Length} characters"); }
 If Length
is zero that means the instance contains no characters.
Check if StringBuilder Is Empty Using String Class Methods
To check if StringBuilder
is empty, we can use the String
class methods as well. But before we do that, we have to convert the StringBuilder instance to a String instance:
var emptyStringBuilder = new StringBuilder(); var emptyString = emptyStringBuilder.ToString();
Then, we can use other String class methods to check emptiness after converting StringBuilder
to a String
class:
var emptyStringBuilder = new StringBuilder(); var converted2String = emptyStringBuilder.ToString(); if (string.IsNullOrEmpty(converted2String)) { Console.WriteLine("emptyStringBuilder is empty!"); }
Or, we can compare directly:
if (emptyStringBuilder.ToString() == "") { Console.WriteLine("emptyStringBuilder is empty!"); }
Lastly, let’s use the String.Empty
property to make the comparison:
if (emptyStringBuilder.ToString() == String.Empty) { Console.WriteLine("emptyStringBuilder is empty!"); }
Now if we start our application and test this implementation, we can see that everything works as expected:
StringBuilder is not empty and lenght is 20 characters emptyStringBuilder is empty! emptyStringBuilder is empty! emptyStringBuilder is empty!
One more thing to mention here. The String
class in C# and .NET (Core) are immutable. That means, even if you use the same string variable, after every operation, a new string object is created. This causes too many memory allocations and it is a costly operation for resources. The StringBuilder
class does not create a new object for every operation so it costs fewer resources to use it.
Conclusion
In this article, we have learned how to check if a StringBuilder
object is empty. We have provided several examples in both a direct way by using the Length
property and an indirect way with the String
class.Â