Convert cookie to object

Parse a Cookie header string into name–value pairs.

JavaScript Version 1.0.0 · MIT · .md

function parseCookies(cookie) { return Object.fromEntries(cookie.split(';').filter(item => item.includes('=')).map(item => [item.slice(0, item.indexOf('=')).trim(), item.slice(item.indexOf('=') + 1).trim()])); }

Input & expected output

"theme=dark; session=abc=def; lang=pt-BR"

{
  "theme": "dark",
  "session": "abc=def",
  "lang": "pt-BR"
}

The edge case

""

{}

Know the limits

• The original read document.cookie and split on every =, which cut values such as "abc=def"; this version parses any header string and splits on the first = only.
• Values are not URI-decoded; apply decodeURIComponent where your app encodes them.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Convert Celsius to Fahrenheit — Apply the temperature conversion without rounding the result.
• Convert hex to RGB — Expand #rgb if needed and read the red, green and blue channels.
• Convert URL parameters to object — Read a query string into an object; repeated keys become arrays.