Contending with JS “used before defined” and Titanium Developer

Question

I have a lengthy JavaScript file that passes JSLint except for \"used before it was defined\" errors.

I used normal function declarations, as in...

funct         


        

Answer 1

No, EM's answer is NOT the right solution. Try running this JavaScript:

(function () {
   foo(); // right

   var foo = function () {
     console.log("wrong");
   };

   foo(); // wrong

   function foo() {
     console.log("right");
   }

   foo(); // wrong
}());

This is because the interpreter will first read the function declaration, create the name foo as a function that prints "right", then reads the var statement, and find that there is already a name foo so it will skip creating a new variable with the value undefined, as normally happens. Then it processes the code, line-by-line, which includes an assignment to foo. The function declaration does not get reprocessed. Maybe this will behave differently in Titanium, but try this in Firebug and you'll get what I got.

A better solution is:

var screen1, buildMenu;

screen1 = function () { buildMenu(); };
buildMenu = function () { screen1(); };

This will also pass JSLint, and produce the correct behavior.