How to Reduce Values in a Map to a Single Value in JavaScript

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

Answer

To reduce values in a map to a single value in JavaScript, 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 JavaScript 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 console.log function to verify the result.

JavaScript Program

const myMap = new Map([
    [1, 10],
    [2, 20],
    [3, 30],
    [4, 40],
    [5, 50]
]);

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

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

// Print the sum
console.log('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 JavaScript 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 Number.MIN_SAFE_INTEGER 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 console.log function to verify the result.

JavaScript Program

const myMap = new Map([
    [1, 10],
    [2, 20],
    [3, 30],
    [4, 40],
    [5, 50]
]);

// Declare a variable to store the maximum value
let maxValue = Number.MIN_SAFE_INTEGER;

// Iterate over the original map and find the maximum value
myMap.forEach((value) => {
    if (value > maxValue) {
        maxValue = value;
    }
});

// Print the maximum value
console.log('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 JavaScript 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 console.log function to verify the result.

JavaScript Program

const myMap = new Map([
    [1, 10],
    [2, 20],
    [3, 30],
    [4, 40],
    [5, 50]
]);

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

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

// Print the product
console.log('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 JavaScript language with well detailed examples.

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How to Reduce Values in a Map to a Single Value in JavaScript