I am working on an angular app. I have an array as follow:

data = [
{
 num1:12.233,
 num2: 13.345
},
{
 num1:10.233,
 num2: 23.345
},
{
 num1:18.233,
 num2: 33.345
}
]

Similarly at runtime time I can have many elements. I want to traverse array such that I can add all the num1 and divide them by number of num1 present. For example, I want to write a code which can take num1 from every element

12.233   10.233   18.233 / 3(total num1 elements in array)

Similarly for num2.

How can I do that?

CodePudding user response：

You can simply use reduce to get the total of elements and then divide it with data.length

const data = [
  {
    num1: 12.233,
    num2: 13.345,
  },
  {
    num1: 10.233,
    num2: 23.345,
  },
  {
    num1: 18.233,
    num2: 33.345,
  },
];

const avg = data.reduce((acc, curr) => acc   curr.num1, 0) / data.length;
console.log(avg);

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

For average of num2 then you can similarly do as:

const avg = data.reduce((acc, curr) => acc   curr.num2, 0) / data.length;

---

You can also get the average using a single iteration as:

const data = [
  {
    num1: 12.233,
    num2: 13.345,
  },
  {
    num1: 10.233,
    num2: 23.345,
  },
  {
    num1: 18.233,
    num2: 33.345,
  },
];

const [avgNum1, avgNum2] = data
  .reduce((acc, curr) => [acc[0]   curr.num1, acc[1]   curr.num2], [0, 0])
  .map((n) => n / data.length);
console.log(avgNum1, avgNum2);

<iframe name="sif2" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

You can loop through data and add the values of num1 and num2 to a variable, then divide it by the length of data (which is 3).

const data = [
  {
    num1: 12.233,
    num2: 13.345
  },
  {
    num1: 10.233,
    num2: 23.345
  },
  {
    num1: 18.233,
    num2: 33.345
  }
]

let num1 = 0;
let num2 = 0;

for (let i = 0; i < data.length; i  ) {
  num1  = data[i].num1;
  num2  = data[i].num2;
}

const num1Avg = num1 / data.length;
const num2Avg = num2 / data.length;
console.log(`Average of num1: ${num1Avg}`)
console.log(`Average of num2: ${num2Avg}`)

<iframe name="sif3" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

let avg = data.reduce( (accumVariable, curValue) => accumVariable curValue.num1 , 0 ) / data.length