 Why Copy constructor is NOT called to copy the temporary object to the new defined object
By : Bharadwaj Jannu
Date : March 29 2020, 07:55 AM
hope this fix your issue ,
Why?
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 Java clone shallow-copy deep-copy copy-constructor nested object
By : Michael Grabow
Date : March 29 2020, 07:55 AM
will be helpful for those in need That's how the copy constructor and the clone method should be: For the student: code :
//Copy constructor for the student
Student(Student copyCons){
this._rollNo = copyCons._rollNo;
this._name = copyCons._name;
this._address = copyCons._address;
this._teacher = copyCons._teacher.clone();
}
//Clone for the student
protected Student clone(){
return new Student(this);
}
//This is the copy constructor
Teacher(Teacher t){
setName(t.getName());
}
//That's how you clone an object of type teacher
protected Teacher clone(){
return new Teacher(this);
}
Teacher t1 = new teacher("Teacher 1");
Teacher t1Clone = t1.clone();
Student s1 = new Student(15007, "Amit", "Chirimiri", t1);
Student s1Clone = s1.clone();
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How to append/copy an STL container object to another object when its value is not copy constructible e.g. std::thread
By : Sibu Stephen
Date : March 29 2020, 07:55 AM
help you fix your problem std::thread is not copy-constructible, you'll have to use an iterator that allows moves: code :
m1.insert(std::make_move_iterator(m2.begin()),
std::make_move_iterator(m2.end());
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 copy object with objects avoiding mutation of the initial object (avoid copy references)
By : Dheeraj Mittal
Date : March 29 2020, 07:55 AM
I wish this help you I have a question regarding copy of object by reference , use this way: code :
let a = {
"0": {
"sortPluginSettings": {
"columnSortType": "numeric",
"sortingOrder": "noSort"
}
}
}
var b= JSON.parse(JSON.stringify(a));
b[0].sortPluginSettings.columnSortType=null;
console.log(a);
console.log(b);
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 Why is a copy of a pandas object altering one column on the original object? (Slice copy)
By : Programmer
Date : March 29 2020, 07:55 AM
may help you . As I understand, a copy by slicing copies the upper levels of a structure, but not the lower ones. code :
In [44]: lst = [[1, 2], 3, 4]
In [45]: lst2 = lst[:]
In [46]: lst2[1] = 100
In [47]: lst # unchanged
Out[47]: [[1, 2], 3, 4]
In [48]: lst2[0].append(3)
In [49]: lst # changed
Out[49]: [[1, 2, 3], 3, 4]
In [50]: arr = np.array([1, 2, 3])
In [51]: arr2 = arr[:]
In [52]: arr2[0] = 100
In [53]: arr
Out[53]: array([100, 2, 3])
In [62]: df = pd.DataFrame([[1, 2, 3], [4, 5, 6]])
In [63]: df
Out[63]:
0 1 2
0 1 2 3
1 4 5 6
In [64]: df2 = df[:]
In [65]: df2.iloc[0, 0] = 100
In [66]: df
Out[66]:
0 1 2
0 100 2 3
1 4 5 6
dfmi['one']['second'] = value
# becomes
dfmi.__getitem__('one').__setitem__('second', value)
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code :
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