Global Properties and Functions Defined in ECMAScript

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∟Global Properties and Functions Defined in ECMAScript

This section provides a quick description of all global properties and functions mentioned in the ECMAScript specification.

There 3 built-in global properties with primitive values contained in the invisible "Global" object mentioned in the ECMAScript specification:

"NaN" - A global property that holds the special number value: NaN (Not A Number).
"Infinity" - A global property that holds the special number value: Infinity.
"undefined" - A global property that holds the undefined value: undefined.

There are 9 regular built-in global functions contained in the invisible "Global" object mentioned in the ECMAScript specification:

"eval(x)" - Evaluates the specified string a JavaScript expression and returns the result.
"parseInt(string, radix)" - Produces an integer value dictated by interpretation of the contents of the string argument according to the specified radix.
"parseFloat(string)" - Produces a number value dictated by interpretation of the contents of the string argument as a decimal literal.
"isNaN(number)" - Returns true if the specified number is NaN.
"isFinite(number)" - Returns true if the specified number is a finite number.
"decodeURI(encodedURI)" - Decodes an encoded URI string back to a URI string.
"decodeURIComponent(encodedURIComponent))" - Decodes an encoded URI component string back to a URI component string.
"encodeURI(uri)" - Encodes a URI string by replacing all characters except the following: alphabetic, decimal digits, - _ . ! ~ * ' ( ) # ; , / ? : @ & = + $, with escape sequences.
"encodeURIComponent(uriComponent)" - Encodes a URI component string by replacing all characters except the following: alphabetic, decimal digits, - _ . ! ~ * ' ( ), with escape sequences.

There are 9 special built-in global functions contained in the invisible "Global" object mentioned in the ECMAScript specification. These functions are really constructors of built-in object types:

"Object()" - Constructor of the Object object type.
"Function(...)" - Constructor of the Function object type.
"Array(...)" - Constructor of the Array object type.
"String(...)" - Constructor of the String object type.
"Boolean(...)" - Constructor of the Boolean object type.
"Number(...)" - Constructor of the Number object type.
"Date(...)" - Constructor of the Date object type.
"RegExp(...)" - Constructor of the RegExp object type.
"Error(...)" - Constructor of the Error object type.

There 1 built-in global properties with an object value contained in the invisible "Global" object mentioned in the ECMAScript specification:

"Math" - A global property that holds the default "Math" object which contains all mathematics related properties and functions.

In order to verify those global properties and functions, I wrote this simple script:

// Global_Object_Properties.js
// Copyright (c) 2013 HerongYang.com. All Rights Reserved.

   println("\nGlobal primitive-value properties:");
   println("   NaN: Type = "+(typeof this.NaN) 
      + ", Value = "+this.NaN);
   println("   Infinity: Type = "+(typeof this.Infinity) 
      + ", Value: "+this.Infinity);
   println("   undefined: Type = "+(typeof this.undefined) 
      + ", Value = "+this.undefined);

   println("\nGlobal functions:");
   println("   eval: Value = "+this.eval);
   println("   parseInt: Value = "+this.parseInt);
   println("   parseFloat: Value = "+this.parseFloat);
   println("   isNaN: Value = "+this.isNaN);
   println("   isFinite: Value = "+this.isFinite);
   println("   decodeURI: Value = "+this.decodeURI);
   println("   decodeURIComponent: Value = "+this.decodeURIComponent);
   println("   encodeURI: Value = "+this.encodeURI);
   println("   encodeURIComponent: Value = "+this.encodeURIComponent);

   println("\nGlobal constructors:");
   println("   Object: Value = "+this.Object);
   println("   Function: Value = "+this.Function);
   println("   Array: Value = "+this.Array);
   println("   String: Value = "+this.String);
   println("   Boolean: Value = "+this.Boolean);
   println("   Number: Value = "+this.Number);
   println("   Date: Value = "+this.Object);
   println("   RegExp: Value = "+this.RegExp);
   println("   Error: Value = "+this.Error);

   println("\nGlobal object-value property:");
   println("   Math: Type = "+(typeof this.Math) 
      + ", Value = "+this.Math);

If you run this script with "jrunscript", you will get:

Global primitive-value properties:
   NaN: Type = number, Value = NaN
   Infinity: Type = number, Value: Infinity
   undefined: Type = undefined, Value = undefined

Global functions:
   eval: Value = function eval() { [native code
   parseInt: Value = function parseInt() { [native code
   parseFloat: Value = function parseFloat() { [native code
   isNaN: Value = function isNaN() { [native code
   isFinite: Value = function isFinite() { [native code
   decodeURI: Value = function decodeURI() { [native code
   decodeURIComponent: Value = function decodeURIComponent() { [native
   encodeURI: Value = function encodeURI() { [native code
   encodeURIComponent: Value = function encodeURIComponent() { [native

Global constructors:
   Object: Value = function Object() { [native code
   Function: Value = function Function() { [native code
   Array: Value = function Array() { [native code
   String: Value = function String() { [native code
   Boolean: Value = function Boolean() { [native code
   Number: Value = function Number() { [native code
   Date: Value = function Object() { [native code
   RegExp: Value = function RegExp() { [native code
   Error: Value = function Error() { [native code

Global object-value property:
   Math: Type = object, Value = [object Math]