Logic inside List.map

Question

I want to include logic inside my list mapping. Example:

I can do something like this:

List projects = urls.map((url) => url.substring(0, 3)).toList();

But can I, somehow, do something like this:

List projects = urls.map((url) {
  if (url.indexOf("?") == -1) {
    url;
  } else {
    url.substring(0, url.indexOf("?"));
  }
}).toList();

Answer 1

Of course you can. What is missing is a return statement.
With the short function format (=>) return is implicit and the result of the expression gets returned. If you use the function block format you have to explicitly return the value you want to have in the result. Without an explicit return null is returned.

List projects = urls.map((url) {
  if (url.indexOf("?") == -1) {
    return url;
  } else {
    return url.substring(0, url.indexOf("?"));
  }
}).toList();