Java and JavaScript: A brief comparison
When it comes to programming languages most people think that Java and JavaScript are somehow related to each other. Even I thought that they are somehow related to each other until I did some research on it. It turns out that the naming of JavaScript is just a marketing move because of the gaining popularity of java at the time of the release of JavaScript rather than because of the similarities of the two languages. Yes, they have some similarities when it comes to syntax and object-oriented concepts but there are so many differences to make them just another two distinct programming languages rather than being similar.
What is Java?
Java is a multi-platform, object-oriented, and network-centric, programming language and uses mainly JVM (Java Virtual machine) to execute code. Java promises the “Write once, run anywhere” concept so that any machine that has JVM installed can run Java. Project “Oak” Started in 1991 by James Gosling for Sun microsystems and it took 4 years to develop the language then later released in 1995 by the name of Java and was later acquired by Oracle Corporation. Java is among the most used programming languages in the world.
What is JavaScript?
JavaScript is a lightweight programming language (“scripting language”) and used to make web pages interactive. It can insert dynamic text into HTML. JavaScript is also known as the browser’s language. Unlike Java, JavaScript was developed in just 10 days. A developer named Brendan Eich at Netscape Inc. developed the language name “LiveScript” and because of the increasing popularity of Java at the time, Netscape decided to rename the language as “JavaScript”.
Similarities
It would be false to say that Java and JavaScript are only similar to each other only from the name and have no other similarities at all. Both languages require the developer to code in terms of objects and their relationships to one another. By extension, this gives both languages access to OOP techniques like inheritance, encapsulation, and polymorphism. Java and JS both extend their applications in front-end development. JavaScript can be embedded directly into HTML, implemented as a framework or library and Java can be used as a Java applet. Other than front-end support both languages offer server-side support. Java supports major back-end technologies such as JBoss, Apache, and WebSphere. Node.js serve JavaScript-powered servers.
Key differences
- Class-Based vs Prototype Based
Java follows class-based inheritance. A top-down, hierarchical, class-based relationship whereby properties are defined in a class and inherited by an instance of that class (one of its members). In JavaScript, inheritance is prototypal — all objects can inherit directly from other objects. Hierarchy is accomplished in JavaScript by assigning an object as a prototype with a constructor function.
- Multi-Threaded vs Single Threaded
Multi-threading reduces execution time by executing more than one part of the program concurrently, thereby utilizing CPU power. Java supports multi-threading, whereas JavaScript does not support it as the interpreter inside the browser is single-threaded.
- Compiled vs. Interpreted
Java is considered a compiled programming language. JavaScript is considered an interpreted scripting language. The difference is in the implementation: Java is compiled into byte-code and runs on a virtual machine, whereas JavaScript can be interpreted directly by a browser in the syntax it is written (although it is usually minified in practice). With the advent of JIT compiling, JavaScript can also be compiled into optimized byte-code.
- Static vs Dynamic Type Checking
Java uses static type checking, where the type of a variable is checked at compile-time. The programmer must specify the type (integer, double, string, etc.) of any variable they create. JavaScript, like most scripting languages, uses dynamic typing, where type safety is verified at runtime. It is not required for a programmer to specify the type of any variable they create.
- Programming paradigm
The significant difference between the two languages is their programming paradigm. Java is an OOP language is based on the concepts of objects. On the other hand, JavaScript is a multi-paradigm language and can be used as OOP, procedural or scripting language.
- Function Overloading
Functioning overloading allows the programming language to define two or more functions with the same name for executing different tasks. The functions, however, differ based on their arguments. Java supports function overloading, whereas JavaScript does not.
- Inheritance
The concept of inheritance allows an entity to inherit or derive the properties of another entity. Java allows a class to derive the properties of another class. It also supports multiple inheritances which means a class can derive properties from multiple classes whereas JavaScript is based on the concept of prototypes and does not support multiple inheritances.
The bottom line
JavaScript shares some similarities with Java, but also some huge differences. Both languages offer OOP concepts like abstraction, polymorphism to make interactive and secure making web applications. There are also huge differences when considering programming paradigms, type checking and execution methods. Because of these differences, each of the languages has advantages/disadvantages in different types of development projects.
