How to Reduce Values in a Map to a Single Value in Dart - Step by Step Examples

How to Reduce Values in a Map to a Single Value in Dart ?

Answer

To reduce values in a map to a single value in Dart, you can iterate over the map and accumulate the values using a specific operation, such as summation. This method allows you to combine all the values in the map into a single result based on the specified operation.

✐ Examples

1 Summing All Values in a Map

We can sum all the values in a map in Dart by iterating over the map and accumulating the values into a single sum.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has integer keys and integer values.
We declare a variable named sum and initialize it to 0 to store the accumulated sum of the values.
We iterate over the original map using the forEach method and add each value to the sum variable.
We print the sum to the console using the print function to verify the result.

Dart Program

void main() {
    // Declare and initialize a map
    Map<int, int> myMap = {
        1: 10,
        2: 20,
        3: 30,
        4: 40,
        5: 50
    };

    // Declare a variable to store the sum of values
    int sum = 0;

    // Iterate over the original map and sum the values
    myMap.forEach((key, value) {
        sum += value;
    });

    // Print the sum
    print('Sum of all values: $sum');
}

Output

Sum of all values: 150

2 Finding the Maximum Value in a Map

We can find the maximum value in a map in Dart by iterating over the map and keeping track of the highest value encountered.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has integer keys and integer values.
We declare a variable named maxValue and initialize it to the minimum integer value to store the maximum value found in the map.
We iterate over the original map using the forEach method and update the maxValue variable if the current value is greater than the current maxValue.
We print the maximum value to the console using the print function to verify the result.

Dart Program

void main() {
    // Declare and initialize a map
    Map<int, int> myMap = {
        1: 10,
        2: 20,
        3: 30,
        4: 40,
        5: 50
    };

    // Declare a variable to store the maximum value
    int maxValue = myMap.values.reduce((a, b) => a > b ? a : b);

    // Print the maximum value
    print('Maximum value: $maxValue');
}

Output

Maximum value: 50

3 Calculating the Product of All Values in a Map

We can calculate the product of all the values in a map in Dart by iterating over the map and multiplying the values into a single product.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has integer keys and integer values.
We declare a variable named product and initialize it to 1 to store the accumulated product of the values.
We iterate over the original map using the forEach method and multiply each value into the product variable.
We print the product to the console using the print function to verify the result.

Dart Program

void main() {
    // Declare and initialize a map
    Map<int, int> myMap = {
        1: 10,
        2: 20,
        3: 30,
        4: 40,
        5: 50
    };

    // Declare a variable to store the product of values
    int product = 1;

    // Iterate over the original map and multiply the values
    myMap.forEach((key, value) {
        product *= value;
    });

    // Print the product
    print('Product of all values: $product');
}

Output

Product of all values: 12000000

Summary

In this tutorial, we learned How to Reduce Values in a Map to a Single Value in Dart language with well detailed examples.

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How to Reduce Values in a Map to a Single Value in Dart - Step by Step Examples