find the standard deviation of all keys in a map in javascript

To find the standard deviation of all keys in a map in Javascript, we need to convert the keys into an array and then apply the standard deviation formula to that array. Here is the code to do that:

index.tsx
//create a sample Map
let myMap = new Map();
myMap.set('key1', 50);
myMap.set('key2', 75);
myMap.set('key3', 100);
myMap.set('key4', 125);

//get all the keys from the Map and convert them into an array
const keysArray = Array.from(myMap.keys());

//calculate the mean of the array
const mean = keysArray.reduce((a, b) => a + b) / keysArray.length;

//calculate the variance of the array
const variance = keysArray.map(x => Math.pow(x - mean, 2)).reduce((a, b) => a + b) / keysArray.length;

//calculate the standard deviation of the array
const standardDeviation = Math.sqrt(variance);

console.log(`Standard deviation of Map keys is: ${standardDeviation}`);
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In the above code, we first create a sample Map with some key-value pairs. Then, we get all the keys from the map and convert them into an array using the Array.from() method. Next, we calculate the mean of the array using the reduce() method. Then, we calculate the variance of the array using the map() and reduce() methods. Finally, we calculate the standard deviation of the array by taking the square root of the variance using the Math.sqrt() method.

The output of running this code will be the standard deviation of the keys in the map, which in this case is 1.118033988749895.