title: Is there a way to reliably delete/wipe a variable (i.e. key/password) in JavaScript?
body: <p>Today crypto libraries for JavaScript exists <a href="http://crypto.stanford.edu/sjcl/" rel="nofollow">sjcl</a> and hence there may be the situation that 
  a password/key/secret/sensitivedata is stored somewhere in a variable in JavaScript. </p>
  
  <p>I do not want to risk that this sensitve data is leaked/disclosed and hence I would very much like to know if there is a way to reliably wipe a variable in Javascript so that the memory used by the JavaScript Engine will not have any remaining info about he data? I would for instance not want to rely on some GC to wipe the data lazily etc.</p>
  
  <p>An answer might feature an example code that kills/wipes a variable and also an explanation when (and if there are differences on what JavaScript implementation Browsers type /Nodejs) it makes sence to trust that the data has been deleted?</p>
  
  <p>Else if the task is impossible I would appreciate a explanation why this is so as well and also accept this as an answer</p>
  
  <p>The goal is not to protect the webpage user from accessing the script variable (this cannot be done I guess). The goal is more to guarantee that the memory of the javascript engine does not keep shadow/cached copies of the data, after the point necessary. I do want to have the data be gone so that no-one (attacker software) can get the secret data via looking at the memory been associated with the Javascript Variables.</p>