CSV to JSON Conversion: A Complete Guide

CSV (Comma Separated Values) is the universal language of spreadsheet exports. However, when you're moving that data into a modern web app or a NoSQL database, you need JSON. Converting them isn't always as simple as splitting by commas.

The Basic Logic

A standard CSV is a flat table. JSON allows for hierarchy. When you convert CSV to JSON, you are essentially turning each row into an object and mapping the column headers to keys.

Why Delimiters Matter

Despite the name, a "Comma Separated" file might actually use semicolons (common in Europe), tabs (TSVs), or pipes. A robust converter must detect the delimiter or allow you to specify it.

Dealing with Embedded Commas

What happens if a cell contains a comma? E.g., "London, UK". In a properly formatted CSV, this field is wrapped in quotes. A simple String.split(',') will break here. You need a parser that understands "Escaped Fields."

Handling Data Types

CSV is inherently text-based. Everything is a string. When converting to JSON, you often want to cast specific columns:

• Booleans: Convert "true", "yes", or "1" to true.
• Numbers: Convert "123.45" to a numeric type.
• Empty Strings: Should they be "" or null?

Example Transformation

-- CSV Input --
id,name,active
1,"Jane Doe",true

-- JSON Output --
[
  {
    "id": 1,
    "name": "Jane Doe",
    "active": true
  }
]