Remove property key using filter()

Question

var a = [{'id':1,'name':'James','age':11}];

a = a.filter(function( obj,i ) {
            //return obj != 'age';
          });

filter will create a new array, but how to splice away the age property key? Didn't use jquery, can't use $.grep in this case. and won't use delete because it's not really delete the key but leave an empty slot.

That's an array of object(s). You are iterating through the array elements not the properties of first child of the array which is an object, i.e. you should iterate twice. — Ram, May 02 '16 at 08:27
Could you add an example of the desired end product? Do you know about all the keys in the object in advance, or is that dynamic? — thriqon, May 02 '16 at 08:37
For reference, `delete` will [**not** leave an empty slot](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/delete). — Yoshi, May 02 '16 at 08:47

score 3 · Accepted Answer · edited Jun 30 '17 at 13:03

3

Use Array#forEach and delete operator to delete the key

var a = [{
  'id': 1,
  'name': 'James',
  'age': 11
}, {
  'id': 2,
  'name': 'James2'
}];

a.forEach(function(obj, i) {
  obj['age'] && delete obj['age'];
});
console.log(a);

edited Jun 30 '17 at 13:03

Jed Fox

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answered May 02 '16 at 08:28

Rayon

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delete will not remove the key but left an empty slot – Jamie Jordan May 02 '16 at 08:32
@JamieJordan [No it doesn't](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/delete). – Yoshi May 02 '16 at 08:38
@JamieJordan That’s only for arrays. It works properly for plain objects. – Jed Fox Jun 30 '17 at 13:04

score 0 · Answer 2 · edited May 02 '16 at 12:04

0

Please try this:

a = [{'id':1,'name':'James','age':11}];
b = a.map(function(v, i) {
    var copy = {};
    for(key in v) {
        if(key != 'age') {
            copy[key] = v[key];
        }
    }
    return copy;
});

edited May 02 '16 at 12:04

Andrei

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answered May 02 '16 at 08:36

Sergey Gornostaev

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score -2 · Answer 3 · edited May 02 '16 at 08:43

-2

var a = [{'id':1,'name':'James','age':11}];

a = a.filter(function( obj,i ) {
    if(obj.hasOwnProperty('age')) {
        delete obj.age
        return obj;
    }
});

edited May 02 '16 at 08:43

Yoshi

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answered May 02 '16 at 08:32

Anish Chandran

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Please specify the final o/p you want ? – Anish Chandran May 02 '16 at 08:44

Remove property key using filter()

3 Answers3