What is the difference between javascript and C programming language?

Answer 1

Mainly JavaSript is a low-level scripting language that differs from the high-level languages in its easiness. The core language is really simple, and is designed to be easier for beginners,

I.e. JS i loosly typed. Meaning that a variable can reference any kind of literal, array or object, which differs from the high-level C-languages where you have to declare if a variable i to reference an integer, floating-point, string, hash-map and so on.

Another major difference is that JS, like python or php isn't compiled to machine code, but interpreted at runtime, making programs run significantly slower than compiled programs.

Another difference which is good, and unique to JS is that it does not inherit the C class model when working in OOP. Objects in JavaScripts can be crated and altered as one want to, beeing more dynamic to work with. A classical model can however be adopted with use of functions and use of the 'new' keyword. Here the lack of private variables can be worked around by the use of a technique called 'closure'.

The major difference however is that programs written in JS to work with the HTML DOM tend to not follow the normal procedural 'step-by-step' executions as conventional programs, where one line of code is being executed at the time. In stead JS tend to follow a Event Loop model, where different parts of the programs are attached to different DOM events. The JS-program will then sleep until a event is fired, then wake up, do its job, then go back to sleep. And so on. All in all making JS a very dynamic and "fun to work with" language.

Answer 2

JavaScript is run in a web browser or a scripting engine, and does not need to be compiled into a binary to run. It can not generally access the system's hardware or storage, and has severe limitations on any other resources it has access to (memory, CPU time, etc). It can run on any system that can run JavaScript without source code modification (e.g. Windows, Linux, Mac OS, Solaris, PS3, etc).

C must be compiled to be executed, runs on the user's computer with substantially more trust than a web page, can access all of the system's hardware and other resources (within the limits of the operating system's permissions). It must be compiled for a specific type of hardware and cannot run on its own when placed on different hardware. As an example, a Mac cannot run C compiled for Windows.