How to omit specific properties from an object in JavaScript

Question

Is there a clean way to return a new object that omits certain properties that the original object contains without having to use something like lodash?

Answer 1

var obj = {
  a: 1,
  b: 2,
  c: 3,
  d: {
    c: 3,
    e: 5
  }
};

Object.extract = function(obj, keys, exclude) {
  var clone = Object.assign({}, obj);
  if (keys && (keys instanceof Array)) {
    for (var k in clone) {
      var hasKey = keys.indexOf(k) >= 0;
      if ((!hasKey && !exclude) || (hasKey && exclude)) {
        delete clone[k];
      }
    }
  }
  return clone;
};

console.log('Extract specified keys: \n-----------------------');
var clone1 = Object.extract(obj, ['a', 'd']);
console.log(clone1);
console.log('Exclude specified keys: \n-----------------------');
var clone2 = Object.extract(obj, ['a', 'd'], true);
console.log(clone2);

Answer 2

function omitKeys(obj, keys) {
        var target = {}; 

        for (var i in obj) { 
            if (keys.indexOf(i) >= 0) continue;
            if (!Object.prototype.hasOwnProperty.call(obj, i)) continue; 

            target[i] = obj[i]; 
        } 

        return target; 
    }