The standardization effort for JavaScript needed to avoid trademark issues, so the ECMA 262 standard calls the language ECMAScript, three editions of which have been published since the work started in November 1996.
Objective-J is a strict superset of JavaScript that adds traditional inheritance and Smalltalk/Objective-C style dynamic dispatch and optional pseudo-static typing to pure JavaScript.
Microsoft's VBScript, like JavaScript, can be run client-side in web pages. VBScript has syntax derived from Visual Basic and is only supported by Microsoft's Internet Explorer.
JSON, or JavaScript Object Notation, is a general-purpose data interchange format that is defined as a subset of JavaScript.
JavaScript is also considered a functional programming language[1] like Scheme and OCaml because it has closures and supports higher-order functions.[44]
Mozilla browsers currently support LiveConnect, a feature that allows JavaScript and Java to intercommunicate on the web. However, support for LiveConnect is scheduled to be phased out in the future.
JavaScript and Java
A common misconception is that JavaScript is similar or closely related to Java; this is not so. Both have a C-like syntax, are object-oriented, are typically sandboxed and are widely used in client-side Web applications, but the similarities end there. Java has static typing; JavaScript's typing is dynamic (meaning a variable can hold an object of any type and cannot be restricted). Java is loaded from compiled bytecode; JavaScript is loaded as human-readable code. C is their last common ancestor language.
Nonetheless, JavaScript was designed with Java's syntax and standard library in mind. In particular, all Java keywords are reserved in JavaScript, JavaScript's standard library follows Java's naming conventions, and JavaScript's Math and Date objects are based on classes from Java 1.0.
No comments:
Post a Comment