Flutter String Concatenation breaking when last string is file extension

July 21, 2022

I’m trying to concatenate some strings which will eventually be part of a URL, but the result of the concatenation is always missing the last string which is a file extension.
I’ve tried all the official ways of concatenating. Here is my latest attempt where I tried to merge the strings by using the join method on a String List.

  String? resColor = color?.label;
  String? resCategory = category?.label;

  print(resColor!.length);
  List<String> refSplit = [
    'previewAssets/',
    resCategory!,
    '/',
    resColor!,
    '.jpg'
  ];

  for (int i = 0; i < refSplit.length; i++) {
    print(refSplit[i]);
  }
  String ref = refSplit.join('');
  print(refSplit);
  print(ref);

My excepted outcome is obviously that ref would contain all items from refSplit. But it doesn’t.

Here is the output from the prints: output

Im knida new to flutter but I feel like concatenating strings shouldn’t be this hard, so I’m probably missing something obvious. Any help would be greatly appreciated.

>Solution :

I tried your code and it seems to work fine in dartpad

void main() {
  List<String> refSplit = [
    'previewAssets/',
    'something',
    '/',
    '109',
    '.jpg'
  ];
  String ref = refSplit.join("");
  print(ref);
}