add or push a 10th index number to the array

Question

I was working on a chart where i need my data to be sliced into small object based for better visibility. My array that i have is

   {
      "size":[
        {
          "timestamp":"1641329889000",
          "size":12345,
          "fees":123456,
          "cost":168
        },
        {
          "timestamp":"1641387032",
          "size":456789,
          "fees":4567891,
          "cost":249
        },
        {
          "timestamp":"1641435786",
          "size":98765,
          "fees":987654,
          "cost":987
        },
        {
          "timestamp":"1641435786",
          "size":98765,
          "fees":987654,
          "cost":987
        },
        {
          "timestamp":"1641435786",
          "size":98765,
          "fees":987654,
          "cost":987
        }
      ]
    }

in which i want the array to be in this form

{
  "size":{
    "timestamp": ["1641329889000","1641387032","1641435786"],
    "size": [12345,456789,98765],
    "fees": [123456,4567891,987654],
    "cost": [168,249,987]
  }
}

i can achieve this using foreach and push like this

 result.forEach(element => {
     this.state.timestamp.push(element.timestamp);
     this.state.size.push(element.size);
  });

But i want this array to have the items only from the 10,20,30,40th index alone I want not all the value. the values should be chosen only in the basis of x+10 Could anyone help me on this

Answer 1

Instead of forEach why not just use a for loop, and on the condition use the modulus % operator with 10? Like if (i % 10 == 0) inside of the for loop, or just increment i by 10 like i+=10.