Check if multiple objects are equal

Compare JSON serializations with the first object.

JavaScript Version 1.0.0 · MIT · .md

function areEqual(objects) { return objects.every(object => JSON.stringify(object) === JSON.stringify(objects[0])); }

Input & expected output

[
  {
    "a": 1
  },
  {
    "a": 1
  },
  {
    "a": 1
  }
]

true

The edge case

[
  {
    "a": 1,
    "b": 2
  },
  {
    "b": 2,
    "a": 1
  }
]

false

Know the limits

• Key order matters to JSON.stringify, as the edge case shows; undefined values and functions are dropped. Use a deep-equality library for robust comparison.

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

• Pick properties from an object — Build a new object with only the requested own properties.
• Omit properties from an object — Keep the own enumerable fields that are not in a supplied list.
• Create an object from pairs of key and value — Turn [key, value] pairs into a plain object with Object.fromEntries.