CODEWITHSUNDEEP
javascriptobjectkey-value
HattrickNZ
HattrickNZ

Reputation: 4643

How to return certain keys from an object

this is my object:

a={"a":"1","b":"2","c":"3","d":"4","e":"5","f":"6"}

This returns all the keys:

Object.keys(a)
["a", "b", "c", "d", "e", "f"]

This returns all the keys except 'a':

Object.keys(a).filter(function(k) {return k !== 'a'})
["b", "c", "d", "e", "f"]

how can I return all keys except 1 or more keys for example a or b or c?

I have tried a few permutations but can't seem to get it, 1 below, or maybe it's not possible this way?

Object.keys(a).filter(function(k) {return k !== ('a','b')})
["a", "c", "d", "e", "f"]

Upvotes: 1

Views: 6129

Answers (3)

madox2
madox2

Reputation: 51841

ES6 (ECMAScript 2015) you can use arrow functions:

Object.keys(a).filter(k => !~['a', 'b', 'c'].indexOf(k));

ES6 is not supported by all environments, so you can use ES5 alternative:

Object.keys(a).filter(function(k) {
    return !~['a', 'b', 'c'].indexOf(k);
});

Upvotes: 2

Sebastien Daniel
Sebastien Daniel

Reputation: 4778

Object.keys(a).filter(function(k) {
  return ["a", "b"].indexOf(k) === -1;
});

Just add the keys you want in the matched Array (one used with indexOf)

If you want something more portable:

function excludeKeys(obj, keys) {
   return Object.keys(obj).filter(function(k) {
      return keys.indexOf(k) === -1;
    });
}

This way you can add any amount of excluded keys.

Upvotes: 2

isvforall
isvforall

Reputation: 8926

var a = ["a", "b", "c", "d", "e", "f"]

var b = a.filter(function(k) {return ['a','b'].indexOf(k) < 0})

// b => [ 'c', 'd', 'e', 'f' ]

Upvotes: 0

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