How can I write the lambda expression in optionObject.Forms.First(f => f.FormId == formId).MultipleIteration to a Func so at the end I have something like
Func<FormObject, bool> FormID = f => f.formID == passedVal;
and then use it on the first expression to get something like
optionObject.Forms.First(FormID).MultipleIteration
I tried
Func<FormObject, PassedVal, bool> FormID => formID == PassedVal;
but did not work.
Please note that there is nothing wrong with the lambda expression, it works fine. I am just trying to create a function to replace the expression with the name of the function to make the code look shorter and maintainable.
One option that lets you reuse the function body with new passed values is to generate Func<FormData, bool> instances in a class-level function:
public static Func<FormObject, bool> CreateFormValidFunc(int validId)
{
return f => f.formID == validId;
}
Then you can use it like this:
optionObject.Forms.First(CreateFormValidFunc(passedVal)).MultipleIteration
optionObject.Forms.First(CreateFormValidFunc(2)).MultipleIteration
An interesting side note is that int Foo => 0; is "expression-bodied properties" syntax (new to C# 6.0), and your attempt might have matched it just enough to make the error messages confusing.
You can use expression-bodied methods to reduce the validation func generator to:
public static Func<FormObject, bool> CreateFormValidFunc(int validId) => f => f.formID == validId;