Finding average using function forEach

August 17, 2022

How can I find the average of an object(number) using function forEach?

     var people =[{ 
    name = "John"
    number = "283.37"
    },{
   name = "Susan"
   number = "125,44"
   },{
  name = "Karen"
  number = "98,7"
  }];

    var sum = 0;
people.forEach(function(num) { sum += num});


  average = sum / people.length;
  console.log(average);

I get the Nan error

>Solution :

You have some syntax issues in your object literal. And then you must first convert your number prop to something that can be added. I use parseFloat() to make number from string.

var people = [{
  name:"John",
  number:"283.37"
}, {
  name: "Susan",
  number: "125,44"
}, {
  name:"Karen",
  number: "98,7"
}];

var sum = 0;
people.forEach(function(item) {
  sum += parseFloat(item.number);
});


average = sum / people.length;
console.log(average);

Or you can do this with Array.reduce():

var people = [{
  name:"John",
  number:"283.37"
}, {
  name: "Susan",
  number: "125,44"
}, {
  name:"Karen",
  number: "98,7"
}];

const average = people.reduce((a, b) => (a +  parseFloat(b.number)), 0) / people.length;
console.log(average);