Modifying object in place javascript

Question

I have an object that looks like this:

  var serviceData = {};

  serviceData.energy = {commission:15.00, retention:0.00, conversion:0.099, renewal: false, offset:0, rental: true}
  serviceData.homeMedia = {commission:20.00, retention:0.00, conversion:0.02, renewal: false, offset:0, rental: true}
  serviceData.removal = {commission:4.00, retention:0.00, conversion:0.05, renewal: false, offset:2, rental: true}
  serviceData.storage = {commission:6.00, retention:0.09, conversion:0.01, renewal: true, offset:2, rental: true}
  serviceData.homeContents = {commission:50.00, retention:0.55, conversion:0.40, renewal: true, offset:0, rental: false}

I want to loop over the serviceData and if an item's property rental is false I want to remove that item from serviceData without actually modifying the serviceData object. In other words, create a new object minus the 'removed' item.

How can I do this???

Did you try using delete ... delete serviceData.homeContents; — Musa
– Musa, Commented Dec 22, 2015 at 22:55

Amit · Accepted Answer · 2015-12-22 22:53:57Z

2

Just iterate the object keys and only set the ones you want in the new object:

var serviceData = {};

serviceData.energy = {commission:15.00, retention:0.00, conversion:0.099, renewal: false, offset:0, rental: true}
serviceData.homeMedia = {commission:20.00, retention:0.00, conversion:0.02, renewal: false, offset:0, rental: true}
serviceData.removal = {commission:4.00, retention:0.00, conversion:0.05, renewal: false, offset:2, rental: true}
serviceData.storage = {commission:6.00, retention:0.09, conversion:0.01, renewal: true, offset:2, rental: true}
serviceData.homeContents = {commission:50.00, retention:0.55, conversion:0.40, renewal: true, offset:0, rental: false}

var filtered = {};
for(var key in serviceData) {
  if(serviceData[key].rental) {
    filtered[key] = serviceData[key];
  }
}

document.write(JSON.stringify(filtered, '\n'));

Note that the new object points to the same items ("sub-objects"), it's a shallow copy.

answered Dec 22, 2015 at 22:53

Amit

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1 Comment

Robbo Over a year ago

pretty much had this on my screen but couldn't quite get there. thanks for this

synthomat · Accepted Answer · 2015-12-22 22:45:26Z

1

First Object.assign(...) to copy the whole object, then use a "filter" function to sort out entries based on your rule.

Or use a mapfunction to return values based on your rule, then use "filter" to sort out all null entries.

Just as a hint to have a starting point…

answered Dec 22, 2015 at 22:45

synthomat

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1 Comment

Robbo Over a year ago

my initial thought was to filter but i don't know how to do that on an object literal

mat3e · Accepted Answer · 2015-12-22 23:28:18Z

1

I like using lodash library for strange manipulations :)

var newObj = _.omit(serviceData, function(property) {
    return !property.rental;
});

edited Dec 22, 2015 at 23:28

answered Dec 22, 2015 at 23:12

mat3e

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Comments

Mike Cluck · Accepted Answer · 2015-12-22 22:44:51Z

0

You could use a for-in loop and ignore the key of the item with a false rental.

function copyData(obj, ignoreKey) {
  var copiedObj = {};
  for (var key in obj) {
    if (key === ignoreKey) {
      continue;
    }
    copiedObj[key] = obj[key];
  }
  return copiedObj;
}
var newObject = copyObj(serviceData, 'homeContents');

answered Dec 22, 2015 at 22:44

Mike Cluck

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Comments

maioman · Accepted Answer · 2015-12-22 23:17:39Z

0

you can use jquery each method:

var res={};
    $.each(serviceData, function( index ) {
  if(serviceData[index].rental)
   res[index] = serviceData[index]
})

pen

edited Dec 22, 2015 at 23:17

answered Dec 22, 2015 at 23:09

maioman

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4 Comments

Jimbo Jonny Over a year ago

Why would you use jQuery for this?

maioman Over a year ago

@JimboJonny with JQuery each method you can iterate over object properties as if it was an array ( the method corresponds to [].forEach() ), it's just a way of abstracting the for-in loop

Jimbo Jonny Over a year ago

@maioman - But there's zero need for an index here, so why not just use a for-in loop? Even when you have jQuery already in a project there's no sense in using it in places where it doesn't even provide an advantage. It's even significantly more verbose and complex to write, requiring callback anonymous functions and such.

maioman Over a year ago

@JimboJonny this is a simple case, but using a forEach mehod on an object is quite cool ..

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