Flutter/Dart How to: Different ways to iterate a list of elements

In Dart programming, a List is a growable collection of elements. It serves as a dynamic data structure allowing the addition, removal, and iteration of elements while preserving their insertion order.

This post presents various methods for iterating through a List of objects in Dart and Flutter programming.

#Dart List Iteration Examples

There are multiple approaches to iterate through a List in Dart.

#For Loop with Index

This is a fundamental for loop, commonly found in most programming languages. It initializes the index to 0 and iterates through each element until the condition list.length is met.

Example:

void main() {
  List<String> words = ["one", "two", "three"];
  print(words);
  for (int i = 0; i < words.length; i++) {
    print(words[i]);
  }
}

Output:

[one, two, three]
one
two
three

#Enhanced For-In Loop

The enhanced for-in loop simplifies iterating through the list of objects and elements.

void main() {
  List<String> words = ["one", "two", "three"];
  print(words);
  for (final word in words) {
    print(word);
  }
}

Output:

[one, two, three]
one
two
three

#Using forEach Method

The forEach method offers a concise way to iterate through elements using a lambda function.

Syntax:

void forEach(void Function(String) action)

Iterates each element and executes a function with each element.

void main() {
  List<String> words = ["one", "two", "three"];
  print(words);
  words.forEach((item) {
    print(item);
  });
}

#While Looping in Dart

The while loop provides an alternative method for iterating through elements using boolean expressions.

void main() {
  List<String> words = ["one", "two", "three"];
  print(words);
  var k = 0;
  while (k < words.length) {
    print(words[k]);
    k++;
  }
}

Output:

[one, two, three]
one
two
three

#Conclusion

In Summary, These methods offer readability in iterating through lists in dart programming.