For example, the function object that is the initial value of the *"map"* property of the Array prototype object is described under the subclause heading «Array.prototype.map (callbackFn [ , thisArg])» which shows the two named arguments callbackFn and thisArg, the latter being optional; therefore the value of the *"length"* property of that function object is *1*𝔽.
Unless otherwise specified, the *"length"* property of a built-in function object has the attributes { [[Writable]]: *false*, [[Enumerable]]: *false*, [[Configurable]]: *true* }.
-Every built-in function object, including constructors, has a *"name"* property whose value is a String. Unless otherwise specified, this value is the name that is given to the function in this specification. Functions that are identified as anonymous functions use the empty String as the value of the *"name"* property. For functions that are specified as properties of objects, the name value is the property name string used to access the function. Functions that are specified as get or set accessor functions of built-in properties have *"get"* or *"set"* (respectively) passed to the _prefix_ parameter when calling CreateBuiltinFunction. +
Every built-in function object, including constructors, has a *"name"* property whose value is a String. Unless otherwise specified, this value is the name that is given to the function in this specification. Functions that are identified as anonymous functions use the empty String as the value of the *"name"* property. For functions that are specified as properties of objects, the name value is the property name string used to access the function. Functions that are specified as get or set accessor functions of built-in properties have *"get"* or *"set"* (respectively) passed to the _prefix_ parameter when calling CreateBuiltinFunction.
The value of the *"name"* property is explicitly specified for each built-in functions whose property key is a Symbol value. If such an explicitly specified value starts with the prefix *"get "* or *"set "* and the function for which it is specified is a get or set accessor function of a built-in property, the value without the prefix is passed to the _name_ parameter, and the value *"get"* or *"set"* (respectively) is passed to the _prefix_ parameter when calling CreateBuiltinFunction.
Unless otherwise specified, the *"name"* property of a built-in function object has the attributes { [[Writable]]: *false*, [[Enumerable]]: *false*, [[Configurable]]: *true* }.
Every other data property described in clauses