Excel to JSON

Transform an excel or csv file into JSON string.

For example, transform sheet data like below...
PRODUCT NAME COLOR CATEGORY PRICE
Apple MacBook Pro 17" Silver Laptop $2999
Microsoft Surface Pro White Laptop $1999
Magic Mouse 2 Black Accessories $99

into this!

{
  "columns": [
    "PRODUCT NAME",
    "COLOR",
    "CATEGORY",
    "PRICE"
  ],
  "rows": [
    {
      "PRODUCT NAME": "Apple MacBook Pro 17\"",
      "COLOR": "Silver",
      "CATEGORY": "Laptop",
      "PRICE": "$2999"
    },
    {
      "PRODUCT NAME": "Microsoft Surface Pro",
      "COLOR": "White",
      "CATEGORY": "Laptop",
      "PRICE": "$1999"
    },
    {
      "PRODUCT NAME": "Magic Mouse 2",
      "COLOR": "Black",
      "CATEGORY": "Accessories",
      "PRICE": "$99"
    }
  ]
}