JavaScript equivalent to printf/String.Format

Question

I\'m looking for a good JavaScript equivalent of the C/PHP printf() or for C#/Java programmers, String.Format() (IFormatProvider for .

Answer 1

I have a solution very close to Peter's, but it deals with number and object case.

if (!String.prototype.format) {
  String.prototype.format = function() {
    var args;
    args = arguments;
    if (args.length === 1 && args[0] !== null && typeof args[0] === 'object') {
      args = args[0];
    }
    return this.replace(/{([^}]*)}/g, function(match, key) {
      return (typeof args[key] !== "undefined" ? args[key] : match);
    });
  };
}

Maybe it could be even better to deal with the all deeps cases, but for my needs this is just fine.

"This is an example from {name}".format({name:"Blaine"});
"This is an example from {0}".format("Blaine");

PS: This function is very cool if you are using translations in templates frameworks like AngularJS:

 {{('hello-message'|translate).format(user)}} 

 {{('hello-by-name'|translate).format( user ? user.name : 'You' )}} 

Where the en.json is something like

{
    "hello-message": "Hello {name}, welcome.",
    "hello-by-name": "Hello {0}, welcome."
}