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I'm trying to add an extra parameter to a list of ef objects to track processing, but I keep running into having to initialize each list item explicitly. What's the correct linq way to do this? Aside from terseness, is there any advantage to a linq syntax in this case?
List<app_subjects> subjectList = AppMySQLQueries.GetAllSubjects();
List<Tuple<app_subjects, bool>> subjectCollection = new List<Tuple<app_subjects, bool>>(subjectList.Count);
foreach (app_subjects subject in subjectList)
{
subjectCollection.Add(Tuple.Create(subject, false));
}
I have searched the site without success.
222
A simple way to convert a list of lists to a list of tuples is to start with an empty list. Then iterate over each list in the nested list in a simple for loop, convert it to a tuple using the tuple() function, and append it to the list of tuples.
To convert the Python list to a tuple, use the tuple() function. The tuple() is a built-in function that passes the list as an argument and returns the tuple. The list elements will not change when it converts into a tuple.
You just want to use a projection here ( Select ) which applies the transformation in your lambda expression to each element in the source collection.
List<Tuple<app_subjects, bool>> tuples = subjectList.Select(x => new Tuple<app_subjects, bool>(x, false)).ToList();
The ToList() call is not entirely necessary, if you removed it then the method will return an IEnumerable<Tuple<app_subjects, bool>>. If you're just going to iterate the collection of tuples afterwards the ToList call should be removed as it forces execution (enumerates the IEnumberable) and then your next operation (the foreach) would do the same, making the code perform worse.
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