create a json from array of string using javascript

Question

After scraping an html table I have stored my data in the variable:

var data = ["header1", "header2", "a1", "a2", "b1", "b2", "c1", "c2"];

I want to create a json file in the form:

var json = [
  {
    "header1":"a1", 
    "header2":"a2"
  },
  {
    "header1":"b1", 
    "header2":"b2"
  },
  {
    "header1":"c1", 
    "header2":"c2"
  }
]

I know that I need

var headers={};

and load it with

headers["header1"]
headers["header2"]

I also need

var jsonObj = [];

and push the array headers inside jsonObj:

jsonObj.push(headers);

Is it possible to create it?

There's no such thing as a "JSON array" (or ["JSON object"](http://benalman.com/news/2010/03/theres-no-such-thing-as-a-json/)). `json` is an array of objects. There's no [JSON](https://www.json.org/json-en.html) at all in your question. — Andreas, Oct 19 '21 at 09:54
[What is the difference between JSON and Object Literal Notation?](https://stackoverflow.com/questions/2904131/what-is-the-difference-between-json-and-object-literal-notation) — Andreas, Oct 19 '21 at 09:54
I have a large number of data in my real code and I am trying to understand how to loop in the array of strings and "isolate" the headers.. — sqlQueryAll, Oct 19 '21 at 09:58
How do you differentiate between which value going to header1 and which one to header2? — , Oct 19 '21 at 10:03
It is always like that.. First two elements are my headers and then data[2], data[4] .. go to header1 and data[3], data[5]... go to header2 — sqlQueryAll, Oct 19 '21 at 10:06

score 1 · Accepted Answer · answered Oct 19 '21 at 10:09

I'll make some assumptions, and then attempt to answer your question.

To me, it seems your table looks something like:

header1	header2
a1	a2
b1	b2
c1	c2

Simply starting with the array you already have, we can then just pick out two and two values at the time. See the code below

const COLUMN_COUNT = 2
const data = ["header1", "header2", "a1", "a2", "b1", "b2", "c1", "c2"]

// this removes the headers from the data-list, 
// and stores them in the headers variable
const headers = data.splice(0, COLUMN_COUNT)
const output = []

while(data.length > 0) {
  const row = {}
  const values = data.splice(0, COLUMN_COUNT)
  for(const [idx, value] of values.entries()) {
    const header = headers[idx]
    row[header] = value
  }
  output.push(row)
}

console.log(output)

Correct. Thank you very much – sqlQueryAll Oct 19 '21 at 10:10 — sqlQueryAll, Oct 19 '21 at 10:10

score 0 · Answer 2 · answered Oct 19 '21 at 10:13

There is actually no relation between header and the values, but assuming the first two elements are always header1 and header2 and the next 1 pair will be the value of header1 and header2 respectively, this might do it

const data = ["header1", "header2", "a1", "a2", "b1", "b2", "c1", "c2"];
const res = [];
const h1 = data[0];
const h2 = data[1];
data.splice(0, 2);


for (let i = 0; i < data.length; i++) {
    if (i % 2 != 0) {
        const payload = {};
        payload[h1] = data[i - 1];
        payload[h2] = data[i];
        res.push(payload);
    }
}

console.log(res)

create a json from array of string using javascript

2 Answers2