Skip to content

meanBy

Calculates the average of an array of numbers when applying the getValue function to each element.

If the array is empty, this function returns NaN.

Signature

typescript
export function meanBy<T>(items: T[], getValue: (element: T) => number): number;

Parameters

  • items (T[]): An array to calculate the average.
  • getValue ((item: T) => number): A function that selects a numeric value from each element.

Returns

(number): The average of all the numbers as determined by the getValue function.

Examples

typescript
meanBy([{ a: 1 }, { a: 2 }, { a: 3 }], x => x.a); // Returns: 2
meanBy([], x => x.a); // Returns: NaN

Source

SourceDocsTest Case

Contributors

Changelog

No recent changes

Made with ❤️