Despite its popularity, few know that JavaScript is a very nice dynamic object-oriented general-purpose programming language. How can this be a secret? Why is this language so misunderstood?


The Name


The Java- prefix suggests that JavaScript is somehow related to Java, that it is a subset or less capable version of Java. It seems that the name was intentionally selected to create confusion, and from confusion comes misunderstanding. JavaScript is not interpreted Java. Java is interpreted Java. JavaScript is a different language.

Java- 前綴很容易使人聯想到Java,并認為它是Java的子集或簡化版的Java。看起來最初給它選這個名字是別有用心的,是故意混淆概念、故意制造"誤解"的。JavaScript不是解釋執行的Java。Java是解釋執行的Java。JavaScript是另外一種語言。

JavaScript has a syntactic similarity to Java, much as Java has to C. But it is no more a subset of Java than Java is a subset of C. It is better than Java in the applications that Java (fka Oak) was originally intended for.


JavaScript was not developed at Sun Microsystems, the home of Java. JavaScript was developed at Netscape. It was originally called LiveScript, but that name wasn't confusing enough.

JavaScript不是Sun Microsystems的產品,Sun是Java的家。JavaScript是在Netscape被開發出來的。它最初叫LiveScript,嗯……還是這個名字好。

The -Script suffix suggests that it is not a real programming language, that a scripting language is less than a programming language. But it is really a matter of specialization. Compared to C, JavaScript trades performance for expressive power and dynamism.


Lisp in C's Clothing


JavaScript's C-like syntax, including curly braces and the clunky for statement, makes it appear to be an ordinary procedural language. This is misleading because JavaScript has more in common with functional languages like Lisp or Scheme than with C or Java. It has arrays instead of lists and objects instead of property lists. Functions are first class. It has closures. You get lambdas without having to balance all those parens.

JavaScript的類C語法,包括大括號和語句的形式,讓它看起來像普通的面向過程編程語言。這是一種誤解,因為JavaScript和函數式語言,比如 Lisp 或 Scheme,有更多的相似之處,而不是和C或Java。它使用數組而不是列表,使用對象而不是屬性列表。函數是第一位的,它有閉包(closures),另外你還可以使用lambda表達式。



JavaScript was designed to run in Netscape Navigator. Its success there led to it becoming standard equipment in virtually all web browsers. This has resulted in typecasting. JavaScript is the George Reeves of programming languages. JavaScript is well suited to a large class of non-Web-related applications

JavaScript最初被設計成在Netscape Navigator中運行,它在Navigator中的成功引領它成為事實上所有web瀏覽器的標準裝備。這就造就了"類型轉換"。JavaScript是編程語言中的 George Reeves(超人),是大量非web程序的稱職之選。

Moving Target


The first versions of JavaScript were quite weak. They lacked exception handling, inner functions, and inheritance. In its present form, it is now a complete object-oriented programming language. But many opinions of the language are based on its immature forms.


The ECMA committee that has stewardship over the language is developing extensions which, while well intentioned, will aggravate one of the language's biggest problems: There are already too many versions. This creates confusion.


Design Errors


No programming language is perfect. JavaScript has its share of design errors, such as the overloading of + to mean both addition and concatenation with type coercion, and the error-prone with statement should be avoided. The reserved word policies are much too strict. Semicolon insertion was a huge mistake, as was the notation for literal regular expressions. These mistakes have led to programming errors, and called the design of the language as a whole into question. Fortunately, many of these problems can be mitigated with a good lint program.

沒有什么編程語言是完美的。JavaScript也有它設計上的錯誤,比如重載的+號隨著類型的不同既表示"相加"又表示"連接",和本該避免的有錯誤傾向的 with 語句。它的保留字策略過于嚴格。分號的插入是一個巨大的錯誤,比如作為字面正則表達式的符號時。這些失誤已直接導致編程中的錯誤,也使這門語言的整體設計遭人質疑。還好,這些問題中有許多都可以在良好的 lint 程序中得以緩解。

The design of the language on the whole is quite sound. Surprisingly, the ECMAScript committee does not appear to be interested in correcting these problems. Perhaps they are more interested in making new ones.


Lousy Implementations


Some of the earlier implementations of JavaScript were quite buggy. This reflected badly on the language. Compounding that, those implementations were embedded in horribly buggy web browsers.


Bad Books


Nearly all of the books about JavaScript are quite awful. They contain errors, poor examples, and promote bad practices. Important features of the language are often explained poorly, or left out entirely. I have reviewed dozens of JavaScript books, and I can only recommend one: JavaScript: The Definitive Guide (4th Edition) by David Flanagan. (Attention authors: If you have written a good one, please send me a review copy.)

幾乎所有的JavaScript書都是相當可怕的。它們包含錯誤,包含不好的例子,并鼓勵不好的做法。JavaScript語言的一些重要特性它們要么沒有解釋清楚,要么根本就沒有提及。我看過很多JavaScript的書,但我只能推薦一本:David Flanagan著的 JavaScript: The Definitive Guide (4th Edition)

Substandard Standard


The official specification for the language is published by ECMA. The specification is of extremely poor quality. It is difficult to read and very difficult to understand. This has been a contributor to the Bad Book problem because authors have been unable to use the standard document to improve their own understanding of the language. ECMA and the TC39 committee should be deeply embarrassed.




Most of the people writing in JavaScript are not programmers. They lack the training and discipline to write good programs. JavaScript has so much expressive power that they are able to do useful things in it, anyway. This has given JavaScript a reputation of being strictly for the amateurs, that it is not suitable for professional programming. This is simply not the case.




Is JavaScript object-oriented? It has objects which can contain data and methods that act upon that data. Objects can contain other objects. It does not have classes, but it does have constructors which do what classes do, including acting as containers for class variables and methods. It does not have class-oriented inheritance, but it does have prototype-oriented inheritance.


The two main ways of building up object systems are by inheritance (is-a) and by aggregation (has-a). JavaScript does both, but its dynamic nature allows it to excel at aggregation.


Some argue that JavaScript is not truly object oriented because it does not provide information hiding. That is, objects cannot have private variables and private methods: All members are public.


But it turns out that JavaScript objects can have private variables and private methods. (Click here now to find out how.) Of course, few understand this because JavaScript is the world's most misunderstood programming language.

但是事實是JavaScript 的對象可以有私有變量和私有方法(點擊這里來看如何實現)。當然,之所以很少有人知道這個是因為JavaScript是世界上誤解最深的語言嘛。

Some argue that JavaScript is not truly object oriented because it does not provide inheritance. But it turns out that JavaScript supports not only classical inheritance, but other code reuse patterns as well.




中文翻譯地址: 譯者:袁曉輝

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  1. 深藍


    2013-07-15 02:08 回復
  2. airoschou


    2013-04-08 16:20 回復