How to use setInterval without using global variables? I'd prefer to wrap all variables of function invoked by setInerval in some kind of closure, like so:

var wrap = function (f){
 var local1, local2, ...;
 return function () { return f(); }
}

This doesn't work, but the idea is that I'd pass wrap(f) instead of f to setInterval, so that locals for f are nicely wrapped and don't pollute the global scope.

How to use setInterval without using global variables? I'd prefer to wrap all variables of function invoked by setInerval in some kind of closure, like so:

var wrap = function (f){
 var local1, local2, ...;
 return function () { return f(); }
}

This doesn't work, but the idea is that I'd pass wrap(f) instead of f to setInterval, so that locals for f are nicely wrapped and don't pollute the global scope.

• javascript
• closures
• setinterval

2 Answers 2

javascript don't have dynamic binding.(except this keyword)

use anonymous function can archive your idea. (it called closure)

var fnc = function(){
    var local1, local2;

    return function(){
         // using local1, local2
    }
};

setInterval(fnc, 1000);

I assume you're looking for something like this...

var wrap = function (f){
    var locals = Array.prototype.slice.call(arguments, 1);
    return function () { f.apply(this, locals); }
};


function logger_func() {
    console.log.apply(console, arguments);
}

for (var i = 0; i < 10; i++) {
    setTimeout( wrap(logger_func, i, "foo_" + i), // <-- wrapping i
                i * 1000 );
}

Note that modern environments let you pass extra arguments to setTimeout...

for (var i = 0; i < 10; i++) {
    setTimeout(logger_func, i * 1000, i, "foo_" + i);
}