javascript string interpolation

interpolate.js

String.prototype.interpolate = function(object) {
  return this.replace(/#{([\w0-9]+)}/g, function(val, match) {
    return object[match];
  })
}

String.prototype.evilInterpolate = function() {
  return this.replace(/#{([\w0-9]+)}/g, function(val, match) {
    return eval(match);
  });
}
  
alert("#{foo} IS #{bar}".interpolate({ foo: 'JavaScript', bar: 'FUN' }));

var foo = "JavaScript";
var bar = "FUN";
alert("#{foo} IS #{bar}".evilInterpolate());