Question

I want to be able to do this:

var user1 = {
  name: 'John',
  gender: 'male'
}


var user2 = {
  name: 'James',
  gender: 'male',
  email: '[e-mail]'
}

user1.someSetMethod({email: '[e-mail]'});
user2.someSetMethod({name: 'Jenny', gender: 'female'});

Desired Outcome:

var user1 = {
  name: 'John',
  gender: 'male',
  email: '[e-mail]'
}


var user2 = {
  name: 'Jenny',
  gender: 'female',
  email: '[e-mail]'
}

I want a method that will set attributes according to what is passed into the function. Is the attribute doesn’t exist I want it to be created, if it does, I want it to be overwritten.

Does a method like this exist in Javascript?

Answer 1

This is normally called extending your object. Virtually every JavaScript library has its own method to do this. Or you can write your own in a few lines of code.

• jQuery extend
• underscore.js extend
• ExtJS extend
• MooTools extend
• Prototype extend

Using jQuery’s method, you’d do it like so:

var user1 = {
  name: 'John',
  gender: 'male'
};

$.extend(user1, {
  email: '[e-mail]'
});

user1.email === '[e-mail]'; //true