Check if array contains string in aggregate function in C#

Question

My code:

allScripts += externalJs.Aggregate(allScripts, (current, js) 
            => current + String.Format("<script src=\"{0}\"></script>", js.Url));

I'd like to check if the parameter Url contains the string "jquery".

Answer 1

allScripts += externalJs.Aggregate(allScripts, (current, js) =>js.Url.Contains("jquery") ? current + String.Format("<script src=\"{0}\"></script>", js.Url) : current);

EDIT: Per the comment below, a better answer would be to pre-filter the list:

allScripts += externalJs.Where(js => js.Url.Contains("jquery")).Aggregate(allScripts, (current, js) => current + String.Format("<script src=\"{0}\"></script>", js.Url);

A quick warning with this solution -- it solves the problem as posted, but you're adding the result to "allScripts" but also including it as the seed to the Aggregate, so you'll probably duplicate your original "allScripts" in this case. Solutions are to not provide a seed, or to only use an "=" instead of "+=" on the assignment.

Answer 2

tnx a lot! that worked perfectly, check the last parenthesis.

allScripts += externalJs.Where(js => !js.Url.Contains("jquery-ui")).Aggregate(allScripts, (current, js) => current + String.Format("<script src=\"{0}\"></script>", js.Url));