Try hasattr(): if hasattr(a, ‘property’): a.property See zweiterlinde’s answer below, who offers good advice about asking forgiveness! A very pythonic approach! The general practice in python is that, if the property is likely to be there most of the time, simply call it and either let the exception propagate, or trap it with a try/except … Read more
for in loops over enumerable property names of an object. for of (new in ES6) does use an object-specific iterator and loops over the values generated by that. In your example, the array iterator does yield all the values in the array (ignoring non-index properties).
This function removes duplicate values from an array by returning a new one. function removeDuplicatesBy(keyFn, array) { var mySet = new Set(); return array.filter(function(x) { var key = keyFn(x), isNew = !mySet.has(key); if (isNew) mySet.add(key); return isNew; }); } var values = [{color: “red”}, {color: “blue”}, {color: “red”, number: 2}]; var withoutDuplicates = removeDuplicatesBy(x => … Read more
There are a few steps you need to take to properly store this information in your localStorage. Before we get down to the code however, please note that localStorage (at the current time) cannot hold any data type except for strings. You will need to serialize the array for storage and then parse it back … Read more
Object.keys gets the keys from the object, then you can filter the keys based on the values var obj = {1001: true, 1002: false}; var keys = Object.keys(obj); var filtered = keys.filter(function(key) { return obj[key] }); FIDDLE
It seems like not supporting Extension methods on Object was a design decision in VB. As a result, the only way we could prevent extension methods from completely breaking existing late bound code was to prevent them from being used on anything typed as object. Link
Object cloning is the act of making a copy of an object. As Cody pointed out, cloning in PHP is done by making a shallow copy of the object. This means that internal objects of the cloned object will not be cloned, unless you explicitly instruct the object to clone these internal objects too, by … Read more
Yes, it is called serialization! String serializedObject = “”; // serialize the object try { ByteArrayOutputStream bo = new ByteArrayOutputStream(); ObjectOutputStream so = new ObjectOutputStream(bo); so.writeObject(myObject); so.flush(); serializedObject = bo.toString(); } catch (Exception e) { System.out.println(e); } // deserialize the object try { byte b[] = serializedObject.getBytes(); ByteArrayInputStream bi = new ByteArrayInputStream(b); ObjectInputStream si = … Read more
You can use post_init for this from dataclasses import dataclass @dataclass class One: f_one: int f_two: str @dataclass class Two: f_three: str f_four: One def __post_init__(self): self.f_four = One(**self.f_four) data = {‘f_three’: ‘three’, ‘f_four’: {‘f_one’: 1, ‘f_two’: ‘two’}} print(Two(**data)) # Two(f_three=”three”, f_four=One(f_one=1, f_two=’two’))
The final function does not get called because async.forEach requires that you call the callback function for every element. Use something like this: async.forEach(Object.keys(dataObj), function (item, callback){ console.log(item); // print the key // tell async that that particular element of the iterator is done callback(); }, function(err) { console.log(‘iterating done’); });