JS pivot data from "wide" to "long"

Question

I have tabular data that looks like this:

And ultimately what I want to achieve is this:

The data can be parsed and managed in any way, but it begins it's lifecycle in the tabular format as shown in the first picture.

Answer 1

Edited based on OP's comment.

Let's say input JSON looks like this:

[
...
{
  "record": 1,
  "identity": "student",
  "second_identity": "visitor"
},
{
  "record": 2,
  "identity": "student",
  "second_identity": "resident"
}
...

]

I would convert it to this format:

[
...
{
  "record": 1,
  "identity_long": "student"
},
{
  "record": 1,
  "identity_long": "visitor"
},
{
  "record": 2,
  "identity_long": "student",
},
{
  "record": 2,
  "identity_long": "resident"
}
...

]

Here's the code:

function processData(input) {
  const output = [];
  for (let i = 0; i < input.length; i++) {
    const record = input[i];

    // Add "identity"
    output.push({ record: record.record, identity_long: record.identity });

    // Add "second_identity"
    output.push({ record: record.record, identity_long: record.second_identity });
  }

  return output;
}