Trim a String to a Particular Length

One piece of code that is very popular, besides checking for null, is being able to trim a string to a particular length, making sure a string is not too long to save in the database or display on your page or MVC View. In the olden days, we had lots of code like this:

if (myString.Length > 10)
{
	dbTable.Property = myString.Substring(0,10);
}
else
{
	dbTable.Property = myString;
}

In one form or another. Now, with extension methods, we can add this into our bag of tricks to have available everywhere:

public static class StringExtensions
{
	public static string Trim(this string value, int MaxLength)
	{
		return value.Substring(0, Math.Min(MaxLength, value.Length));
	}
}

Notice that I’m using the Math.Min function to tell the Substring whether to return the string as it is, or use the MaxLength argument. Now the code above will look like this:

dbTable.Property = myString.Trim(10);

And it will save the value of myString as it’s current value, unless it’s longer than 10, which will cause it to be trimmed.

One of the big advantages of using String Extension Methods like this is that they can be used in Linq queries very easily. If you want to see more about extension methods, check out my other posts below:

Jack’s Top 10 String Extension Methods
Extension Method to Convert Types
Linq OrderBy Extension using a string

Author: Jack Yasgar

Jack Yasgar has been developing software for various industries for two decades. Currently, he utilizes C#, JQuery, JavaScript, SQL Server with stored procedures and/or Entity Framework to produce MVC responsive web sites that converse to a service layer utilizing RESTful API in Web API 2.0 or Microsoft WCF web services. The infrastructure can be internal, shared or reside in Azure. Jack has designed dozens of relational databases that use the proper primary keys and foreign keys to allow for data integrity moving forward. While working in a Scrum/Agile environment, he is a firm believer that quality software comes from quality planning. Without getting caught up in analysis paralysis, it is still possible to achieve a level of design that allows an agile team to move forward quickly while keeping re-work to a minimum. Jack believes, “The key to long term software success is adhering to the SOLID design principles. Software written quickly, using wizards and other methods can impress the business sponsor / product owner for a short period of time. Once the honeymoon is over, the product owner will stay enamored when the team can implement changes quickly and fix bugs in minutes, not hours or days.” Jack has become certified by the Object Management Group as OCUP II (OMG Certified UML Professional) in addition to his certification as a Microsoft Certified Professional. The use of the Unified Modeling Language (UML) provides a visual guide to Use Cases and Activities that can guide the product owner in designing software that meets the end user needs. The software development teams then use the same drawings to create their Unit Tests to make sure that the software meets all those needs. The QA testing team can use the UML drawings as a guide to produce test cases. Once the software is in production, the UML drawings become a reference for business users and support staff to know what decisions are happening behind the scenes to guide their support efforts.

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