How to convert all string in Dart list to lowercase?

Question

I want check if Dart list contain string with list.contains so must convert string in array to lowercase first.

How to convert all string in list to lowercase?

For example:

[[email protected], [email protected], [email protected], [email protected], [email protected]]

You can use .any() instead. if (["aBc", "bca"].any((el) => el.toLowerCase() == "abc")) print("contains"); — Oleg Plotnikov, Dec 05 '20 at 15:55
Beware... the local part of the address (to the left of the @) might be _case-sensitive_ (https://stackoverflow.com/questions/9807909/are-email-addresses-case-sensitive). Although you probably won't run into issues, best to leave that alone if you can. — Randal Schwartz, Dec 05 '20 at 20:07

score 11 · Answer 1 · answered Dec 05 '20 at 15:59

You can map through the entire list and convert all the items to lowercase. Please see the code below.

  List<String> emails = ["[email protected]", "[email protected]", "[email protected]", "[email protected]", "[email protected]"];
  emails = emails.map((email)=>email.toLowerCase()).toList();
  print(emails);

score 0 · Answer 2 · answered May 04 '22 at 00:17

Right now with Dart you can use extension methods to do this kind of conversions

extension LowerCaseList on List<String> {
  void toLowerCase() {
    for (int i = 0; i < length; i++) {
      this[i] = this[i].toLowerCase();
    }
  }
}

When you import it, you can use it like

List<String> someUpperCaseList = ["QWERTY", "UIOP"];

someUpperCaseList.toLowerCase();

print(someUpperCaseList[0]); // -> qwerty

score 0 · Answer 3 · answered Jul 28 '22 at 02:50

0

You can try:

List<String> emails = ["[email protected]", "[email protected]", "[email protected]", "[email protected]", "[email protected]"];
 for(String email in emails){
  print(email.toLowerCase());
}

answered Jul 28 '22 at 02:50

Will28

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How to convert all string in Dart list to lowercase?

3 Answers3