title: Javascript - Compiled language?
body: <p>I am new to Web development, and I am studying JavaScript.</p>
  <p>From a <a href="http://web.stanford.edu/class/cs98si/" rel="nofollow noreferrer">course</a> at Stanford:</p>
  <blockquote>
  <p>JavaScript is an interpreted language, not a compiled language. A program such as C++ or Java needs to be compiled before it is run. The source code is passed through a program called a compiler, which translates it into bytecode that the machine understands and can execute. In contrast, JavaScript has no compilation step. Instead, an interpreter in the browser reads over the JavaScript code, interprets each line, and runs it. More modern browsers use a technology known as Just-In-Time (JIT) compilation, which compiles JavaScript to executable bytecode just as it is about to run.</p>
  </blockquote>
  <p>And from <strong><a href="http://shop.oreilly.com/product/0636920026327.do" rel="nofollow noreferrer">You Don't Know JS: Scope &amp; Closures</a></strong> by <a href="https://stackoverflow.com/users/228852/kyle-simpson">Kyle Simpson</a>:</p>
  <blockquote>
  <p>... but despite the fact that JavaScript falls under the general category of “dynamic” or “interpreted” languages, it is in fact a compiled language.</p>
  <p>Let’s just say, for simplicity sake, that any snippet of JavaScript has to be compiled before (usually right before!) it’s executed. So, the JS compiler will take the program  var a = 2; and compile it first, and then be ready to execute it, usually right away.</p>
  </blockquote>
  <p>And from some questions at Stack Overflow, there are some ideas like: It depend on an actual implementation of the language.</p>
  <p>Do you have any ideas?</p>