Check if a value is an object

Return true for any non-null object, including arrays.

JavaScript Version 1.0.0 · MIT · .md

function isObject(value) { return value !== null && typeof value === 'object'; }

Input & expected output

{}

true

The edge case

null

false

Know the limits

• Arrays are objects here; use the plain-object check to exclude 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

• Check whether all values are equal — Compare every item with the first using Object.is.
• Check whether an object is empty — Check for own enumerable string keys on a JSON object.
• Check whether an integer is even — Test parity for safe integers, including zero and negative values.