Why is JSON not valid?

Question

JSON

Can you please tell me why the following JSON is not valid?

{
  "input": {
    "qwe": "1",
    "asd": "1",
  }
}

Checked with a validator

Answer 1

the last comma is extra

Answer 2

{
  "input": {
    "qwe": "1",
    "asd": "1"
  }
}

Remove the comma at the end.