TopLevel
Class Object
The Object object is the foundation of all native JavaScript objects. Also,
the Object object can be used to generate items in your scripts with behaviors
that are defined by custom properties and/or methods. You generally start by creating
a blank object with the constructor function and then assign values to new properties
of that object.
Constructor Summary
Object()
Object constructor.
Method Summary
static assign(target
:
Object, sources
:
Object...)
:
Object
Copies the values of all of the enumerable own properties from one or more source objects to a target object.
static create(prototype
:
Object, properties
:
Object)
:
Object
Creates a new object based on a prototype object and additional property definitions.
static defineProperties(object
:
Object, properties
:
Object)
:
Object
Defines or modifies properties of the passed object.
static defineProperty(object
:
Object, propertyKey
:
Object, descriptor
:
Object)
:
Object
Defines or modifies a single property of the passed object.
static entries(object
:
Object)
:
Array
Returns the enumerable property names and their values of the passed object.
static fromEntries(properties
:
Iterable)
:
Object
Creates a new object with defined properties.
static getOwnPropertyDescriptor(object
:
Object, propertyKey
:
Object)
:
Object
Returns the descriptor for a single property of the passed object.
static getOwnPropertyNames(object
:
Object)
:
Array
Returns an arrays containing the names of all enumerable and non-enumerable properties owned by the passed object.
static getOwnPropertySymbols(object
:
Object)
:
Array
Returns an array containing the symbol of all symbol properties owned by the passed object.
static getPrototypeOf(object
:
Object)
:
Object
Returns the prototype of the passed object.
hasOwnProperty(propName
:
String)
:
boolean
Returns Boolean true if at the time the current object's instance was created its constructor (or literal assignment) contained a property with a name that matches the parameter value.
static is(value1
:
Object, value2
:
Object)
:
boolean
Checks if the two values are equal in terms of being the same value.
static isExtensible(object
:
Object)
:
boolean
Returns if new properties can be added to an object.
isPrototypeOf(prototype
:
Object)
:
boolean
Returns true if the current object and the object passed as a prameter conincide at some point along each object's prototype inheritance chain.
static preventExtensions(object
:
Object)
:
Object
Makes the passed object non-extensible.
propertyIsEnumerable(propName
:
String)
:
boolean
Return true if the specified property exposes itself to for/in property inspection through the object.
static setPrototypeOf(object
:
Object, prototype
:
Object)
:
Object
Changes the prototype of the passed object.
toLocaleString()
:
String
Converts the object to a localized String.
Methods inherited from class
Object
assign, create, create, defineProperties, defineProperty, entries, freeze, fromEntries, getOwnPropertyDescriptor, getOwnPropertyNames, getOwnPropertySymbols, getPrototypeOf, hasOwnProperty, is, isExtensible, isFrozen, isPrototypeOf, isSealed, keys, preventExtensions, propertyIsEnumerable, seal, setPrototypeOf, toLocaleString, toString, valueOf, values
Method Detail
assign
Copies the values of all of the enumerable own properties from one or more source objects to a target object.
API Versioned:
From version 21.2.
Parameters:
target
-
The target object.
sources
-
The source objects.
Returns:
The target object.
create
Creates a new object based on a prototype object.
Parameters:
prototype
-
The prototype for the new object.
Returns:
The newly created object.
create
Creates a new object based on a prototype object and additional property definitions.
The properties are given in the same format as described for defineProperties(Object, Object).
Parameters:
prototype
-
The prototype for the new object.
properties
-
The property definitions.
Returns:
The newly created object.
defineProperties
Defines or modifies properties of the passed object.
A descriptor for a property supports these properties: configurable, enumerable, value, writable, set and get.
Parameters:
object
-
The object to change.
properties
-
The new property definitions.
Returns:
The modified object.
defineProperty
Defines or modifies a single property of the passed object.
A descriptor for a property supports these properties: configurable, enumerable, value, writable, set and get.
Parameters:
object
-
The object to change.
propertyKey
-
The property name.
descriptor
-
The property descriptor object.
Returns:
The modified object.
entries
Returns the enumerable property names and their values of the passed object.
API Versioned:
From version 22.7.
Parameters:
object
-
The object to get the enumerable property names from.
Returns:
An array of key/value pairs ( as two element arrays ) that holds all the enumerable properties of the given object.
freeze
Freezes the passed object. Properties can't be added or removed from the frozen object. Also, definitions of
existing object properties can't be changed. Although property values are immutable, setters and getters can be
called.
Parameters:
object
-
The object to be frozen.
Returns:
The frozen object.
fromEntries
Creates a new object with defined properties. The properties are defined by an iterable that produces two element array like objects, which are the key-value pairs.
Iterables are e.g. Array, Map or any other Iterable.
API Versioned:
From version 22.7.
Parameters:
properties
-
The properties.
Returns:
The newly created object.
getOwnPropertyDescriptor
Returns the descriptor for a single property of the passed object.
Parameters:
object
-
The property owning object.
propertyKey
-
The property to look for.
Returns:
The descriptor object for the property or
undefined if the property does not exist.
getOwnPropertyNames
Returns an arrays containing the names of all enumerable and non-enumerable properties owned by the passed object.
Parameters:
object
-
The object owning properties.
Returns:
An array of strings that are the properties found directly in the passed object.
getOwnPropertySymbols
Returns an array containing the symbol of all symbol properties owned by the passed object.
API Versioned:
From version 21.2.
Parameters:
object
-
The object owning properties.
Returns:
An array of symbol properties found directly in the passed object.
getPrototypeOf
Returns the prototype of the passed object.
Parameters:
object
-
The object to get the prototype from.
Returns:
The prototype object or
null if there is none.
hasOwnProperty
hasOwnProperty(propName
:
String)
:
boolean
Returns Boolean true if at the time the current object's instance was created
its constructor (or literal assignment) contained a property with a name that
matches the parameter value.
Parameters:
propName
-
the property name of the object's property.
Returns:
true if at the object contains a property that matches the parameter, false otherwise.
is
Checks if the two values are equal in terms of being the same value. No coercion is performed, thus -0 and
+0 is not equal and NaN is equal to NaN.
API Versioned:
From version 21.2.
Parameters:
value1
-
The first value.
value2
-
The second value.
Returns:
true if both values are the same value else false.
isExtensible
static isExtensible(object
:
Object)
:
boolean
Returns if new properties can be added to an object. By default new objects are extensible. The methods
freeze(Object), seal(Object) and preventExtensions(Object) make objects
non-extensible.
Parameters:
object
-
The object to check.
Returns:
true if new properties can be added else false.
isFrozen
static isFrozen(object
:
Object)
:
boolean
Returns if the object is frozen.
Parameters:
object
-
The object to check.
Returns:
true if the object is frozen else false.
isPrototypeOf
isPrototypeOf(prototype
:
Object)
:
boolean
Returns true if the current object and the object passed as a prameter conincide
at some point along each object's prototype inheritance chain.
Parameters:
prototype
-
the object to test.
Returns:
true if the current object and the object passed as a prameter conincide at some point, false otherwise.
isSealed
static isSealed(object
:
Object)
:
boolean
Returns if the object is sealed.
Parameters:
object
-
The object to check.
Returns:
true if the object is sealed else false.
keys
Returns the enumerable property names of the passed object.
Parameters:
object
-
The object to get the enumerable property names from.
Returns:
An array of strings that holds all the enumerable properties of the given object.
preventExtensions
Makes the passed object non-extensible. This means that no new properties can be added to this object.
Parameters:
object
-
The object to make non-extensible.
Returns:
The passed object.
propertyIsEnumerable
propertyIsEnumerable(propName
:
String)
:
boolean
Return true if the specified property exposes itself to for/in property
inspection through the object.
Parameters:
propName
-
the property to test.
Returns:
true if the specified property exposes itself to for/in property inspection through the object, false otherwise.
seal
Seals the passed object. This means properties can't be added or removed. Also, property definitions of
existing properties can't be changed.
Parameters:
object
-
The object to be frozen.
Returns:
The sealed object.
setPrototypeOf
Changes the prototype of the passed object.
API Versioned:
From version 21.2.
Parameters:
object
-
The object whose prototype should change.
prototype
-
The object to set as the new prototype.
Returns:
The object with the changed prototype.
toLocaleString
toLocaleString()
:
String
Converts the object to a localized String.
Returns:
a localized version of the object.
toString
toString()
:
String
Converts the object to a String.
Returns:
the String representation of the object.