How to Print a Map in Dart

How to Print a Map in Dart ?

Answer

To print a map in Dart, you can iterate over the map using the forEach method or a for-in loop to print each key-value pair.

✐ Examples

1 Printing a Map Using forEach Method

We can print a map in Dart by iterating over the map using the forEach method and printing each key-value pair.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the forEach method to iterate over each key-value pair in the map. The forEach method takes a function that defines the operation to be performed on each element.
Inside the function, we print the key and value of each pair using the print function.

Dart Program

void main() {
    // Declare and initialize a map
    Map<String, int> myMap = {
        'one': 1,
        'two': 2,
        'three': 3
    };

    // Print the map using forEach
    myMap.forEach((key, value) {
        print('$key: $value');
    });
}

Output

one: 1
two: 2
three: 3

2 Printing a Map Using for-in Loop

We can print a map in Dart by iterating over the map using a for-in loop and printing each key-value pair.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use a for-in loop to iterate over each key-value pair in the map. The loop variable entry represents each key-value pair in the map as a MapEntry object.
Inside the loop, we print the key and value of each pair using the print function.

Dart Program

void main() {
    // Declare and initialize a map
    Map<String, int> myMap = {
        'one': 1,
        'two': 2,
        'three': 3
    };

    // Print the map using a for-in loop
    for (var entry in myMap.entries) {
        print('${entry.key}: ${entry.value}');
    }
}

Output

one: 1
two: 2
three: 3

3 Printing a Map Using Map Entries and for Loop

We can print a map in Dart by iterating over the map entries using a traditional for loop and printing each key-value pair.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the entries property of the map to get a list of map entries. Each entry is a MapEntry object containing a key and a value.
We use a traditional for loop to iterate over the list of entries. The loop variable entry represents each key-value pair in the map.
Inside the loop, we print the key and value of each pair using the print function.

Dart Program

void main() {
    // Declare and initialize a map
    Map<String, int> myMap = {
        'one': 1,
        'two': 2,
        'three': 3
    };

    // Print the map using map entries and a for loop
    var entries = myMap.entries.toList();
    for (int i = 0; i < entries.length; i++) {
        var entry = entries[i];
        print('${entry.key}: ${entry.value}');
    }
}

Output

one: 1
two: 2
three: 3

Summary

In this tutorial, we learned How to Print a Map in Dart language with well detailed examples.

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