find the sum of all keys in a map in typescript

Assuming that the keys of the Map are numbers, you can use the reduce method to iterate over the entries of the Map and accumulate the sum of its keys.

Here's an example code snippet:

index.ts
const myMap = new Map<number, string>();
myMap.set(1, 'one');
myMap.set(2, 'two');
myMap.set(3, 'three');

const sumOfKeys = Array.from(myMap.keys()).reduce((sum, key) => sum + key, 0);
console.log(sumOfKeys); // Output: 6
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In the above example, we first initialize our Map with some key-value pairs. Then we convert the iterator of the Map keys to an array using the Array.from method. Finally, we use the reduce method to accumulate the sum of the array values, starting with an initial value of 0.

Note that if the keys of your Map are not numbers, you may need to perform some additional transformations before you can sum them up.