String Interpolation Vs String Concatenation

I had an instance where I was creating a URL from a mixture of strings and values from a model.

model.Content.NewsPageUrl
 ="/"+newsPage?.Url()+"/?tag="+model.Content.TagPickerValue;

But it was suggested to me that rather using string concatenation, I should use string interpolation

model.Content.NewsPageUrl 
=$"/{newsPage?.Url()}/?tag={model.Content.TagPickerValue}";

So I dug a bit deeper to find out when each should be used.

String interpolation and string concatenation are both used to construct strings, but they have different use cases and advantages. Here are some guidelines on when to use each:

Use string concatenation when:

• Simple Strings: When constructing simple strings with a small number of variables, concatenation can be straightforward and sufficient.
• Performance: In performance-critical sections of code, concatenation using StringBuilder can be more efficient, especially in loops or when constructing large strings.

Use string interpolation when:

• Readability: Interpolation makes the code more readable and easier to understand, especially when dealing with multiple variables.

• Handles formatting more cleanly : You can do $"hello {123} world and not have to manually call ToString() for anything that isn't already a string, and there are shorthands for types that take format strings e.g. $"{DateTime.No:yyyy-MM-dd}

• Complex Strings: When constructing strings that include multiple variables or expressions, interpolation provides a cleaner and more concise syntax.

• Maintainability: Interpolation reduces the risk of errors, such as missing spaces or incorrect variable placements, making the code easier to maintain.

Performance Considerations

• String Interpolation: Internally, string interpolation uses String.Format, which can be less efficient than StringBuilder for constructing large strings or in performance-critical scenarios.
• String Concatenation: For multiple concatenations, especially in loops, using StringBuilder is recommended to avoid creating multiple intermediate string objects.

An example of StringBuilder

var stringBuilder = new StringBuilder();
for (int i = 0; i < 100; i++)
{
   stringBuilder.AppendFormat("Item {0}, ", i);
}
string result = stringBuilder.ToString();

Summary

• Use string interpolation for readability, maintainability, and when dealing with complex strings involving multiple variables.
• Use string concatenation for simple strings or when performance is a critical concern, especially with StringBuilder in loops or large string constructions.

Thanks Belle and Tristan for proof reading and suggesting a few changes. #h5yr