shallow-copy

问题 For copying a list: shallow_copy_of_list = old_list[:] . For copying a dict: shallow_copy_of_dict = dict(old_dict) . But for a set , I was worried that a similar thing wouldn't work, because saying new_set = set(old_set) would give a set of a set? But it does work. So I'm posting the question and answer here for reference. In case anyone else has the same confusion. 回答1: Both of these will give a duplicate of a set: shallow_copy_of_set = set(old_set) Or: shallow_copy_of_set = old_set.copy()

问题 This question already has answers here : What is the difference between a deep copy and a shallow copy? (31 answers) What is the difference between shallow copy, deepcopy and normal assignment operation? (11 answers) Closed 2 years ago . Maybe I don't understand the definition of shallow copy... but i'm very confused: from the docs: Where "s" is a list (but same question applies to dictionaries respectively). "s.copy() | creates a shallow copy of s (same as s[:])" Except I thought s[:] was a

问题 This question already has answers here : What is the difference between a deep copy and a shallow copy? (31 answers) What is the difference between shallow copy, deepcopy and normal assignment operation? (11 answers) Closed 2 years ago . Maybe I don't understand the definition of shallow copy... but i'm very confused: from the docs: Where "s" is a list (but same question applies to dictionaries respectively). "s.copy() | creates a shallow copy of s (same as s[:])" Except I thought s[:] was a

问题 case class Person(var firstname: String, lastname: String) val p1 = Person("amit", "shah") val p2 = p1.copy() p1.firstname = "raghu" p1 p2 p1 == p2 As i went through some documentation which says scala copy method of case class uses shallow copy but output of this example i am not able to crack i have created copy as person p2 from p1 and then i have changed p1.firstname to "raghu" so, in case of shallow copy it should change value of p2.firstname but this is not happening here reference:

问题 I have a class like the following: class Test { private LinkedList<Person> persons = new LinkedList<Person>; public synchronized void remove(Person person) { persons.remove(person); } public List<Person> getAllPersons() { // Clients may iterate over the copy returned and modify the structure. return new ArrayList<Person>(persons); } } persons may be modified concurrently: one is via remove() by one thread and two via the shallow copied instance returned by getAllPersons() . I have tested the

问题 I am trying to create a --shallow-since working clone from a local bare clone but it keeps pulling everything. --depth=N works fine. I'm thinking the issue is I'm using the wrong format? I've tried searching but no where does it explicitly say what format < date > is supposed to be for --shallow-since=< date >. 回答1: Format is YYYY-MM-DD See above comment for what confused me and how that confusion was resolved. 回答2: While the date format is indeed, for instance, YYYY-MM-DD, " git fetch -

问题 As per the example given here, let first:number[] = [1, 2]; let second:number[] = [3, 4]; let both_plus:number[] = [0, ...first, ...second, 5]; console.log(`both_plus is ${both_plus}`); first[0] = 20; console.log(`first is ${first}`); console.log(`both_plus is ${both_plus}`); both_plus[1]=30; console.log(`first is ${first}`); console.log(`both_plus is ${both_plus}`); Spreading shows a deep copy, because all three array's have it's own duplicates, based on below output: both_plus is 0,1,2,3,4

问题 I just came across this concept of var copy = Object.assign({}, originalObject); which creates a copy of original object into the " copy " object. However, my question is, does this way of cloning object create a deep copy or a shallow copy? PS: The confusion is, if it creates a deep copy, then it would be the easiest way to clone an object. 回答1: Forget about deep copy, even shallow copy isn't safe, if the object you're copying has a property with enumerable attribute set to false. MDN : The

问题 Explanation : we come across some situation in which we need to copy one object to another object. In that case, we probably have two solutions: angular.copy() or angular.extend(). Challenge i am facing : As we know angular.copy(source, destination) creates a deep copy of source object and assign it to destination. By writing deep copy, we mean that a new copy of the referred object is made and its working fine. deep copy code : var mySource = {'name' : 'Rohit', 'age' : '24'} var myDest = {}

问题 I have two objects of the same type and need to copy property values from one object to another. There are two options: Use reflection, navigate through the properties of the first object and copy the values. Serialize the first object and deserialize a copy. Both work for my requirement, the question is which do I better use in the terms of speed (cost)? Example class Person { public int ID { get; set; } public string Firsthand { get; set; } public string LastName { get; set; } public int