Getting Keys

Part of the Fundamentals section of Coddy's Dart journey — lesson 61 of 94.

The keys property of a map returns an iterable collection of all the keys in the map. This lets you access just the keys without their values.

Create a map of student scores:

Map<String, int> scores = {
  'Alice': 95,
  'Bob': 85,
  'Charlie': 90
};

Get all the keys from the map:

Iterable<String> studentNames = scores.keys;
print('Student names: $studentNames');

After executing the above code, the output will be:

Student names: (Alice, Bob, Charlie)

You can also iterate through all the keys using a for-in loop:

for (String name in scores.keys) {
  print(name);
}

After executing the above code, the output will be:

Alice
Bob
Charlie

Challenge

Beginner

In this challenge, you'll practice using the keys property to get all the keys from a map. The keys property returns an iterable collection of all the keys in a map.

Complete the code to get all the keys from the fruitPrices map and store them in the fruitNames variable.

Expected output:

(apple, banana, orange)

Cheat sheet

The keys property returns an iterable collection of all keys in a map:

Map<String, int> scores = {
  'Alice': 95,
  'Bob': 85,
  'Charlie': 90
};

Iterable<String> studentNames = scores.keys;
print('Student names: $studentNames'); // Output: Student names: (Alice, Bob, Charlie)

You can iterate through keys using a for-in loop:

for (String name in scores.keys) {
  print(name);
}

Try it yourself

void main() {
  // A map of fruits and their prices
  Map<String, double> fruitPrices = {
    'apple': 1.99,
    'banana': 0.99,
    'orange': 1.49
  };
  
  // TODO: Get all the keys from the fruitPrices map
  // and store them in the fruitNames variable
  var fruitNames;
  
  // This will print all the fruit names
  print(fruitNames);
}