Object Creation

• Object Literals: { key: value }
• Constructor: new Object()
• Object.create(proto, properties?) → Creates an object with a specified prototype.
• Object.assign(target, ...sources) → Copies properties from source objects to the target object. (shallow copy)
• structuredClone(obj) → Performs a deep copy of any structured data. (deep copy)
  • Pros: Supports nested structures, circular references, Map/Set, Date, etc.
  • Note: Does not support functions, symbols, or DOM nodes.

Object Structure & Properties

• Object.keys(obj) → Returns an array of an object's keys.
• Object.values(obj) → Returns an array of an object's values.
• Object.entries(obj) → Returns an array of [key, value] pairs.
• Object.hasOwn(obj, key) (ES2022+) → Safer alternative to .hasOwnProperty().
• Object.hasOwnProperty(key) → Checks if an object has a direct property (not inherited).
• Object.propertyIsEnumerable(key) → Checks if a property is enumerable.
• Object.getOwnPropertyNames(obj) → Returns all property names, including non-enumerable.
• Object.getOwnPropertySymbols(obj) → Returns symbol properties.

Prototype & Inheritance

• Object.getPrototypeOf(obj) → Returns the prototype of an object.
• Object.setPrototypeOf(obj, prototype) → Sets the prototype of an object.
• __proto__ (Deprecated) → Directly modifies an object's prototype (use Object.getPrototypeOf() instead).