Posts Tagged ‘mixins’


Tuesday, September 15th, 2009

Taking the idea of inheritance by property copying a step further, consider this this mixin implementation.

Instead of copying from one object, you can copy from any number of objects.

The implementation is pretty simple - just loop through arguments and copy every property of every object passed to the function.

function mixInThese() {
  var arg, prop, child = {};
  for (arg = 0; arg < arguments.length; arg++) {
    for (prop in arguments[arg]) {
      child[prop] = arguments[arg][prop];
  return child;

Here's how to use it. Pass any number of objects and you and up with a new object that has the properties of them all.

var cake = mixInThese(
 {eggs: 2, large: true}, 
 {butter: 1, salted: true}, 
 {flour: "3 cups"},
 {sugar: "sure!"}