I’m sure we’ve all experienced the great idea of looping through a collection and trying to remove an item from a collection that doesn’t need to be there. You’ll get the infamous “Collection was modified; enumeration operation may not execute”. You can create a new collection and add the ones you want to that one, but that’s extra overhead.
Collection was modified; enumeration operation may not execute
This is a method that you can use that is outside of a foreach loop:
entity.TheBody.Elements.RemoveAll(a => string.IsNullOrWhiteSpace(a.Key));
In this example, I have an email named “entity” with a “TheBody” property that has a collection of Elements. The Elements have two properties, “Key” and “Value”, basically like a Dictionary entry. Creating a new list of elements means a new List<EmailElement> and then a .Clear and .AddRange, which kills more CPU cycles and milliseconds.
However, executing the above line will remove all the items from the collection that meet the criteria in the lambda.
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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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