Lodash is a JavaScript library that works on the top of underscore.js. Lodash helps in working with arrays, strings, objects, numbers, etc.
The _.meanBy() method is used to compute the mean value from the original array by iterating over each element in the array using the Iteratee function. It is almost the same as _.mean() function.
Syntax:
_.meanBy( array, [iteratee = _.identity] )
Parameters: This method accepts two parameters as mentioned above and described below:
- array: It is the array that the method iterates over to get the mean of all the elements.
- iteratee: It is the function that is invoked for every element in the array.
Return Value: This method returns the mean value of the array.
Example 1:
Javascript
// Requiring the lodash library const _ = require( "lodash" ); // Original array var arr = [{ 'n' : 4 }, { 'n' : 2 }, { 'n' : 6 }]; // Use of _.meanBy() method let mean_val = _.meanBy(arr, function (o) { return o.n; }); // Printing the output console.log(mean_val); |
Output:
4
Example 2:
Javascript
// Requiring the lodash library const _ = require( "lodash" ); // Original array var arr = [{ 'n' : 10 }, { 'n' : 5 }, { 'n' : 3 }, { 'n' : 12 }]; // Use of _.meanBy() // method let mean_val = _.meanBy(arr, 'n' ); // Printing the output console.log(mean_val); |
Output:
7.5