Which JS function-declaration syntax is correct according to the standard?

Question

  var foo = function(){ return 1; };
  if (true) {
    function foo(){ return 2; }
  }
  foo(); // 1 in Chrome // 2 in FF
  //I just want to be sure, is FF 4 not \"s         


        

Answer 1

fiddle. This is Undefined Behaviour. It's a mess.

How firefox interprets it is handled by the other answers

How chrome interprets it

var foo = function() { return 1 };
if (true) {
    function foo() {
        return 2;
    }
}
console.log(foo());

What's acctually happening is function foo is being declared then overwritten with a local variable foo immediately.

This gets translated into

function foo() {
    return 2;
}
var foo;
foo = function() { return 1 };
if (true) { }
console.log(foo());