Dart Map forEach()

Map forEach()

Map forEach() method applies given action to each key-value pair of this Map.

Syntax

The syntax to perform an action for each key-value pair of the Map map1 is

map1.forEach(action);

//or

map1.forEach((key, value) {
    //code
});

where action is a function that takes key, value as arguments.

The method returns void.

Examples

Print each of the key-value pair in Map

In the following Dart Program, we take a Map fruits, and print each key-value pair of the Map fruits, using Map.forEach() method.

main.dart

void main() {
    var fruits = {'apple': 25, 'banana': 10, 'cherry': 6};

    fruits.forEach((key, value) {
        print('$key : $value');
    });
}

Output

apple : 25
banana : 10
cherry : 6

Passing function to Map.forEach()

In the following Dart Program, we define a function printKeyValue() that takes key, value of this Map as arguments. We pass this function printKeyValue as argument to forEach().

main.dart

void printKeyValue(key, value) {
    print('$key : $value');
}

void main() {
    var fruits = {'apple': 25, 'banana': 10, 'cherry': 6};

    fruits.forEach(printKeyValue);
}

Output

apple : 25
banana : 10
cherry : 6

Conclusion

In this Dart Tutorial, we learned how to execute a function or action for each key-value pair of this Map, using Map.forEach() method.