_dataRecv has a conditionally declared variable about strophejs HOT 3 OPEN

JavaScript does not have block scope so there is no such thing as a conditionally defined variable. This is a pretty big gotcha in the language, and why it is best practice to define all variables at the top of a function. Strophe violates this principle with impunity (which, is quite bizarre considering the JSLint configuration at the top of the core source file).

from strophejs.

@discordinoffice That's actually wrong. JavaScript hoists variable declarations to the top of the scope and assigns the variable where it was declared. This is the case for everything except for the catch and let block, where it creates a block scope.
Read up: https://developer.mozilla.org/en/JavaScript/Reference/Scope_Cheatsheet#Hoisting

This means that this:

function hoistMe() {
  hoisted = "I'm a hoisted variable";
  alert(hoisted);
  var hoisted;
}

is evaluated as:

function hoistMe() {
  var hoisted; // hoisted to the top of the current scope
  hoisted = "I'm a hoisted variable";
  alert(hoisted);
}

from strophejs.

Thank you for that correction; it is much appreciated! That is pretty esoteric, and is definitely something to be aware of.

from strophejs.