Object Built-ins

Porffor implements the full Object API for object manipulation and property management.

Object Constructor

Object

Creates a new object or converts a value to an object.

Object(value?: any): object

const obj1 = Object();              // {}
const obj2 = Object(null);          // {}
const obj3 = Object({ a: 1 });      // { a: 1 }
const obj4 = Object('hello');       // String object
const obj5 = Object(42);            // Number object

Static Methods

Object.keys

Returns an array of object’s own enumerable property names.

Object.keys(obj: object): string[]

const obj = { a: 1, b: 2, c: 3 };
console.log(Object.keys(obj));  // ['a', 'b', 'c']

const arr = [1, 2, 3];
console.log(Object.keys(arr));  // ['0', '1', '2']

Object.values

Returns an array of object’s own enumerable property values.

Object.values(obj: object): any[]

const obj = { a: 1, b: 2, c: 3 };
console.log(Object.values(obj));  // [1, 2, 3]

const arr = [10, 20, 30];
console.log(Object.values(arr));  // [10, 20, 30]

Object.entries

Returns an array of object’s own enumerable property [key, value] pairs.

Object.entries(obj: object): [string, any][]

const obj = { a: 1, b: 2, c: 3 };
console.log(Object.entries(obj));
// [['a', 1], ['b', 2], ['c', 3]]

// Iterate over entries
for (const [key, value] of Object.entries(obj)) {
  console.log(`${key}: ${value}`);
}

Object.assign

Copies properties from source objects to a target object.

Object.assign(target: object, ...sources: object[]): object

const target = { a: 1 };
const source1 = { b: 2 };
const source2 = { c: 3 };

const result = Object.assign(target, source1, source2);
console.log(result);  // { a: 1, b: 2, c: 3 }
console.log(target);  // { a: 1, b: 2, c: 3 } (modified)

// Clone object
const original = { x: 1, y: 2 };
const clone = Object.assign({}, original);

Object.create

Creates a new object with specified prototype.

Object.create(proto: object | null, propertiesObject?: object): object

const proto = { greet() { return 'Hello'; } };
const obj = Object.create(proto);
console.log(obj.greet());  // 'Hello'

const emptyObj = Object.create(null);  // No prototype

Object.freeze

Freezes an object (makes it immutable).

Object.freeze(obj: object): object

const obj = { a: 1, b: 2 };
Object.freeze(obj);

obj.a = 99;        // Fails silently
obj.c = 3;         // Fails silently
delete obj.b;      // Fails silently

console.log(obj);  // { a: 1, b: 2 }

Object.isFrozen

Checks if an object is frozen.

Object.isFrozen(obj: object): boolean

const obj = { a: 1 };
console.log(Object.isFrozen(obj));  // false

Object.freeze(obj);
console.log(Object.isFrozen(obj));  // true

Object.seal

Seals an object (prevents adding/removing properties).

Object.seal(obj: object): object

const obj = { a: 1, b: 2 };
Object.seal(obj);

obj.a = 99;        // OK (can modify existing)
obj.c = 3;         // Fails (cannot add)
delete obj.b;      // Fails (cannot delete)

console.log(obj);  // { a: 99, b: 2 }

Object.isSealed

Checks if an object is sealed.

Object.isSealed(obj: object): boolean

const obj = { a: 1 };
console.log(Object.isSealed(obj));  // false

Object.seal(obj);
console.log(Object.isSealed(obj));  // true

Object.preventExtensions

Prevents adding new properties to an object.

Object.preventExtensions(obj: object): object

const obj = { a: 1 };
Object.preventExtensions(obj);

obj.a = 99;        // OK (can modify)
obj.b = 2;         // Fails (cannot add)
delete obj.a;      // OK (can delete)

console.log(obj);  // { a: 99 }

Object.isExtensible

Checks if an object is extensible.

Object.isExtensible(obj: object): boolean

const obj = { a: 1 };
console.log(Object.isExtensible(obj));  // true

Object.preventExtensions(obj);
console.log(Object.isExtensible(obj));  // false

Object.getOwnPropertyNames

Returns all own property names (including non-enumerable).

Object.getOwnPropertyNames(obj: object): string[]

const obj = { a: 1, b: 2 };
Object.defineProperty(obj, 'c', {
  value: 3,
  enumerable: false
});

console.log(Object.keys(obj));              // ['a', 'b']
console.log(Object.getOwnPropertyNames(obj)); // ['a', 'b', 'c']

Object.getOwnPropertyDescriptor

Gets a property descriptor.

Object.getOwnPropertyDescriptor(obj: object, prop: string): PropertyDescriptor | undefined

const obj = { a: 1 };
const descriptor = Object.getOwnPropertyDescriptor(obj, 'a');
console.log(descriptor);
// {
//   value: 1,
//   writable: true,
//   enumerable: true,
//   configurable: true
// }

Object.getOwnPropertyDescriptors

Gets all property descriptors.

Object.getOwnPropertyDescriptors(obj: object): { [key: string]: PropertyDescriptor }

const obj = { a: 1, b: 2 };
const descriptors = Object.getOwnPropertyDescriptors(obj);
console.log(descriptors);
// {
//   a: { value: 1, writable: true, enumerable: true, configurable: true },
//   b: { value: 2, writable: true, enumerable: true, configurable: true }
// }

Object.defineProperty

Defines a property with a descriptor.

Object.defineProperty(obj: object, prop: string, descriptor: PropertyDescriptor): object

const obj = {};

Object.defineProperty(obj, 'a', {
  value: 42,
  writable: false,
  enumerable: true,
  configurable: false
});

console.log(obj.a);  // 42
obj.a = 99;          // Fails (not writable)
console.log(obj.a);  // 42

// Accessor property
let _value = 0;
Object.defineProperty(obj, 'b', {
  get() { return _value; },
  set(v) { _value = v * 2; },
  enumerable: true,
  configurable: true
});

obj.b = 5;
console.log(obj.b);  // 10

Object.defineProperties

Defines multiple properties.

Object.defineProperties(obj: object, props: { [key: string]: PropertyDescriptor }): object

const obj = {};

Object.defineProperties(obj, {
  a: { value: 1, writable: true },
  b: { value: 2, writable: false },
  c: { value: 3, enumerable: false }
});

console.log(obj);  // { a: 1, b: 2 }

Object.getPrototypeOf

Gets the prototype of an object.

Object.getPrototypeOf(obj: object): object | null

const obj = {};
const proto = Object.getPrototypeOf(obj);
console.log(proto === Object.prototype);  // true

const arr = [];
console.log(Object.getPrototypeOf(arr) === Array.prototype);  // true

Object.setPrototypeOf

Sets the prototype of an object.

Object.setPrototypeOf(obj: object, proto: object | null): object

const proto = { greet() { return 'Hello'; } };
const obj = {};

Object.setPrototypeOf(obj, proto);
console.log(obj.greet());  // 'Hello'

Object.hasOwn

Checks if object has own property (modern alternative to hasOwnProperty).

Object.hasOwn(obj: object, prop: string): boolean

const obj = { a: 1 };
console.log(Object.hasOwn(obj, 'a'));         // true
console.log(Object.hasOwn(obj, 'toString'));  // false (inherited)

Object.fromEntries

Creates an object from key-value pairs.

Object.fromEntries(entries: Iterable<[string, any]>): object

const entries = [['a', 1], ['b', 2], ['c', 3]];
const obj = Object.fromEntries(entries);
console.log(obj);  // { a: 1, b: 2, c: 3 }

// Reverse of Object.entries
const original = { x: 10, y: 20 };
const entries2 = Object.entries(original);
const copy = Object.fromEntries(entries2);
console.log(copy);  // { x: 10, y: 20 }

Instance Methods

hasOwnProperty

Checks if object has own property.

obj.hasOwnProperty(prop: string): boolean

const obj = { a: 1 };
console.log(obj.hasOwnProperty('a'));         // true
console.log(obj.hasOwnProperty('toString'));  // false

toString

Returns string representation.

obj.toString(): string

const obj = { a: 1 };
console.log(obj.toString());  // '[object Object]'

valueOf

Returns primitive value.

obj.valueOf(): any

const obj = { a: 1 };
console.log(obj.valueOf());  // { a: 1 }

Usage Examples

Object Manipulation

// Merge objects
function merge(...objects) {
  return Object.assign({}, ...objects);
}

const obj1 = { a: 1, b: 2 };
const obj2 = { b: 3, c: 4 };
const merged = merge(obj1, obj2);
console.log(merged);  // { a: 1, b: 3, c: 4 }

Property Iteration

const obj = { a: 1, b: 2, c: 3 };

// Iterate over keys
for (const key of Object.keys(obj)) {
  console.log(key, obj[key]);
}

// Iterate over values
for (const value of Object.values(obj)) {
  console.log(value);
}

// Iterate over entries
for (const [key, value] of Object.entries(obj)) {
  console.log(`${key} = ${value}`);
}

Object Transformation

function mapObject(obj, fn) {
  return Object.fromEntries(
    Object.entries(obj).map(([k, v]) => [k, fn(v)])
  );
}

const obj = { a: 1, b: 2, c: 3 };
const doubled = mapObject(obj, x => x * 2);
console.log(doubled);  // { a: 2, b: 4, c: 6 }

Compiler API

Porffor Global API

Built-in APIs

Object Built-ins

Object Constructor

Object

Static Methods

Object.keys

Object.values

Object.entries

Object.assign

Object.create

Object.freeze

Object.isFrozen

Object.seal

Object.isSealed

Object.preventExtensions

Object.isExtensible

Object.getOwnPropertyNames

Object.getOwnPropertyDescriptor

Object.getOwnPropertyDescriptors

Object.defineProperty

Object.defineProperties

Object.getPrototypeOf

Object.setPrototypeOf

Object.hasOwn

Object.fromEntries

Instance Methods

hasOwnProperty

toString

valueOf

Usage Examples

Object Manipulation

Property Iteration

Object Transformation

See Also

Build docs developers (and LLMs) love

Compiler API

Porffor Global API

Built-in APIs

​Object Constructor

​Object

​Static Methods

​Object.keys

​Object.values

​Object.entries

​Object.assign

​Object.create

​Object.freeze

​Object.isFrozen

​Object.seal

​Object.isSealed

​Object.preventExtensions

​Object.isExtensible

​Object.getOwnPropertyNames

​Object.getOwnPropertyDescriptor

​Object.getOwnPropertyDescriptors

​Object.defineProperty

​Object.defineProperties

​Object.getPrototypeOf

​Object.setPrototypeOf

​Object.hasOwn

​Object.fromEntries

​Instance Methods

​hasOwnProperty

​toString

​valueOf

​Usage Examples

​Object Manipulation

​Property Iteration

​Object Transformation

​See Also

Build docs developers (and LLMs) love

Object Constructor

Object

Static Methods

Object.keys

Object.values

Object.entries

Object.assign

Object.create

Object.freeze

Object.isFrozen

Object.seal

Object.isSealed

Object.preventExtensions

Object.isExtensible

Object.getOwnPropertyNames

Object.getOwnPropertyDescriptor

Object.getOwnPropertyDescriptors

Object.defineProperty

Object.defineProperties

Object.getPrototypeOf

Object.setPrototypeOf

Object.hasOwn

Object.fromEntries

Instance Methods

hasOwnProperty

toString

valueOf

Usage Examples

Object Manipulation

Property Iteration

Object Transformation

See Also