Creating new javascript Object form existing one

Question

I have my original objects as follow. All I need is to just extract few properties from existing one and create new object.

var data = [{
    id: 3,
    name: Axe,
    location: alkt
}, {
    id: 5,
    name: Roy,
    location: grelad
}]

I need my output as,

var data_new = [{
    id: 3,
    name: Axe
}, {
    id: 5,
    name: Roy,
}]

How to implement in underscore js or any simple method. Possible its a large JSON object.

dfsq · Accepted Answer · 2015-07-07 08:58:45Z

4

If there are just few properties you want to extract then simple Array.prototype.map will works fine:

var data = [{
    id: 3,
    name: 'Axe',
    location: 'alkt'
}, {
    id: 5,
    name: 'Roy',
    location: 'grelad'
}]

var result = data.map(function(obj) {
    return {
      id: obj.id,
      name: obj.name
    };
});

alert(JSON.stringify(result, null, 4));

answered Jul 7, 2015 at 8:58

dfsq

193k26 gold badges244 silver badges261 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

connexo Over a year ago

It has to be noted that this will not work in IE8 as it does not support Array.prototype.map.

dfsq Over a year ago

Yes, if IE8 is supported then data.map(function(obj) {}) should be changed to _.map(data, function(obj) {}). Thanks for the note!

connexo Over a year ago

So you suggest if a browser only supports ECMA-Script 3 to use a full-blown library? I mean, we all love underscore.js, but why not just go with a standard approach of a for loop using for..in inside?

dfsq Over a year ago

I assume that OP is already using underscore, so why not use it if IE8 support is necessary. If IE8 is not important then use ES5 map.

Dickens A S · Accepted Answer · 2015-07-07 08:51:11Z

2

Use pick in undescorejs http://underscorejs.org/#pick Or omit http://underscorejs.org/#omit

_.pick({name: 'moe', age: 50, userid: 'moe1'}, 'name', 'age');
=> {name: 'moe', age: 50}
_.pick({name: 'moe', age: 50, userid: 'moe1'}, function(value, key, object) {
  return _.isNumber(value);
});
=> {age: 50}

answered Jul 7, 2015 at 8:51

Dickens A S

4,0743 gold badges27 silver badges53 bronze badges

Comments

fuyushimoya · Accepted Answer · 2015-07-07 08:50:35Z

1

It you want remove each item's location

var data_new = _.map(data, function(item) {
  return _.omit(item, 'location');
});

answered Jul 7, 2015 at 8:50

fuyushimoya

9,8133 gold badges30 silver badges34 bronze badges

Comments

dakab · Accepted Answer · 2015-07-07 09:03:02Z

0

If all you want is remove properties from objects in an array, you could just delete them while iterating with forEach:

var data_new = data;
data_new.forEach(function(obj){ delete obj.location; /* or any other */ });

answered Jul 7, 2015 at 9:03

dakab

5,97510 gold badges46 silver badges71 bronze badges

2 Comments

connexo Over a year ago

forEach is not supported in IE8. Also, OP is asking for a new object, not how to alter the original one.

dakab Over a year ago

There was no premise it had to work in a 4½ year old IE. My link even comprises a polyfill at MDN. An edited copy of the original object ''is'' a new object.

user2036241 · Accepted Answer · 2015-07-07 09:06:47Z

0

$scope.data_new = [];
for(i in $scope.data){
  $scope.data_new.push(
   { id: $scope.data[i].id, name: $scope.data[i].name }
  )
}

answered Jul 7, 2015 at 9:06

user2036241

1 Comment

connexo Over a year ago

I'd recommend not to use for ... in for arrays.

Collectives™ on Stack Overflow

Creating new javascript Object form existing one

5 Answers 5

4 Comments

Comments

Comments

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

4 Comments

Comments

Comments

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related