.join()

The .join() method concatenates (combines) list elements as a string including various separators between them dependent on a user’s need.

Syntax

list-name.join('separator')

• separator: It separates elements in a list using any characters wrapped with single/double quotes. White spaces can be used but aren’t obligatory.

Example

The following code snippet demonstrates the .join() method using a separator without white spaces:

void main() {

  List<String> my_letters = ["Y", "o", "u", " ", "a", "r", "e", " ", "a", "w", "e", "s", "o", "m", "e", "!"];

  String my_message = my_letters.join(""); // No separation whatsoever.
  print(my_message);
}

The output of the above code is:

You are awesome!

In the following example, the asterisk is used as a delimiter between elements.

void main() {

  List<String> languages = ["JavaScript", "Python", "HTML", "CSS"];

  String familiar_with = languages.join(" * "); // Adds an asterisk.
  print(familiar_with);
}

The output of the above code is:

JavaScript * Python * HTML * CSS

In the following example, the separator used between each element is or meaning each task in the list will be separated by the word or.

void main() {

  List<String> chores = ["planting flowers", "vacuuming", "laundry", "ironing", "preparing meals"];

  String planOfDut = chores.join(" or "); // Adds 'or' as a conjunction.
  print(planOfDut);
}

The output of the above code is:

planting flowers or vacuuming or laundry or ironing or preparing meals

The following snippet contains a list which has a predefined text to make it slightly more complex:

void main() {

  List<String> resolutions = ["takeaways", "overtime at work", "binge watching", "cigarettes", "comparing to others", "all-night parties"];

  String wishList = resolutions.join(", No ");

  print('In 2024 I will definitely stick to these simple rules: No ${wishList}.');
}

The output of the above code is:

In 2024 I will definitely stick to these simple rules: No takeaways, No overtime at work, No binge watching, No cigarettes, No comparing to others, No all-night parties.