How to use map() for editing object elements inside array?

Question

I have the following:

const data = [
  { name: "Santa"
    age: 34
  },
  { name: "John"
    age: 23
  }
]

I should edit object elements through map().
For example: I want all age to be 68 and 46 relatively. (×2).

I tried to solve but I couldn't

data = data.map(e => {
      e.age *= 2;
});

Answer 1

You need use a return statement, also use let because your data is not in fact constant:

let data = [{
    name: "Santa",
    age: 34
  },
  {
    name: "John",
    age: 23
  }
]

data = data.map(e => {e.age *= 2; return e;});
console.log(data)