JSFiddle - React, Tailwind, and code Playground

by marektchas

JavaScript

// It works
    var age = [22, 34, 12]

    // Id does not
    var people = [
      {
        name: 'Anna',
        age: 22
      },
      {
        name: 'Tom',
        age: 34
      }, {
        name: 'John',
        age: 12
      },
    ]

    // Computing the average
    let getAverage = arr => {
      let reducer = (total, currentValue) => total + currentValue;
      let sum = arr.reduce(reducer)
      return sum / arr.length;
    }

    let test1 = getAverage(age)
    let test2 = getAverage(people.age)

    // It works
    console.log(test1);

    // Eroror: Cannot read property 'reduce' of undefined at getAverage
    console.log(test2);