c++ when are destructors called?
434523
A destructor is called for a class object when that object passes out of scope or is explicitly deleted. A destructor takes no arguments and has no return type. Its address cannot be taken.
1435420
If several references point to same String without even knowing it, it would be bad if one of the references modified that String value. That's why String objects are immutable.
1076424
Overloading New and Delete operator in c++ New and Delete operators can be overloaded globally or they can be overloaded for specific classes. If these operators are overloaded using member function for a class, it means that these operators are overloaded only for that specific class.
569348
A std::shared_ptr consists of a control block and its resource. Yes, the control block is thread-safe; but no, the access to the resource is not thread-safe. That means, modifying the reference counter is an atomic operation and you have the guarantee that the resource will be deleted exactly once.
179950
The main difference between dispose() and finalize() is that the method dispose() has to be explicitly invoked by the user whereas, the method finalize() is invoked by the garbage collector, just before the object is destroyed.
968000
Delete is an operator while Free is a function. Delete frees the allocated memory and also calls the destructor of the class in c++ while free() does not calls any destructor and only free the allocated memory . Free() uses C run time heap whereas Delete may be overloaded on class basis to use private heap.
359906
Calling a Function When a program calls a function, the program control is transferred to the called function. A called function performs a defined task and when its return statement is executed or when its function-ending closing brace is reached, it returns the program control back to the main program.
624722
What is difference between instantiating a C++ object using new vs. without new? In C++, we can instantiate the class object with or without using the new keyword. If the new keyword is not use, then it is like normal object.
1367312
When delete is used to deallocate memory for a C++ class object, the object's destructor is called before the object's memory is deallocated (if the object has a destructor). If the operand to the delete operator is a modifiable l-value, its value is undefined after the object is deleted.
577881
Java uses only call by value while passing reference variables as well. It creates a copy of references and passes them as valuable to the methods. As reference points to same address of object, creating a copy of reference is of no harm.
925220
vector<int> is non-array, non-reference, and non-pointer - it is being passed by value, and hence it will call copy-constructor. So, you must use vector<int>& (preferably with const , if function isn't modifying it) to pass it as a reference.
1219318
note the [undefined x 1] for the sparse array. Since you deleted an element, it follows that: If you delete an element from an array, the array becomes sparse.
992541
char ZEROARRAY[1024]; at global scope it will be all zeros at runtime. But actually there is a shorthand syntax if you had a local array. If an array is partially initialized, elements that are not initialized receive the value 0 of the appropriate type.
603977
Java does not support pointers, unions, operator overloading and structure. C++ supports pointers, unions, operator overloading and structure. Java supports garbage collection. C++ does not supports garbage collection.
438220
["It acts as the bridge between two classes by operating on their private data's.", 'It is able to access members without need of inheriting the class.', 'It can be used to increase the versatility of overloading operator.', "It provides functions that need data which isn't normally used by the class."]
64399
Constructor will be automatically invoked when an object is created whereas method has to be called explicitly. Constructor needs to have the same name as that of the class whereas functions need not be the same. There is no return type given in a constructor signature (header).
1451617
void* memcpy( void* dest, const void* src,size_t count ); The memcpy() function takes three arguments: dest, src and count. This function when called, copies count bytes from the memory location pointed to by src to the memory location pointed to by dest.