In c++ what does a tilde "~" before a function name signify?
C++C++ Problem Overview
template <class T>
class Stack
{
public:
Stack(int = 10) ;
~Stack() { delete [] stackPtr ; } //<--- What does the "~" signify?
int push(const T&);
int pop(T&) ;
int isEmpty()const { return top == -1 ; }
int isFull() const { return top == size - 1 ; }
private:
int size ;
int top ;
T* stackPtr ;
} ;
C++ Solutions
Solution 1 - C++
It's the destructor, it destroys the instance, frees up memory, etc. etc.
Here's a description from ibm.com:
Destructors are usually used to deallocate memory and do other cleanup for a class object and its class members when the object is destroyed. A destructor is called for a class object when that object passes out of scope or is explicitly deleted.
See https://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_74/rzarg/cplr380.htm
Solution 2 - C++
As others have noted, in the instance you are asking about it is the destructor for class Stack.
But taking your question exactly as it appears in the title:
> In c++ what does a tilde “~” before a function name signify?
there is another situation. In any context except immediately before the name of a class (which is the destructor context), ~ is the one's complement (or bitwise not) operator. To be sure it does not come up very often, but you can imagine a case like
if (~getMask()) { ...
which looks similar, but has a very different meaning.
Solution 3 - C++
It's a destructor. The function is guaranteed to be called when the object goes out of scope.
Solution 4 - C++
This is a destructor. It's called when the object is destroyed (out of life scope or deleted).
To be clear, you have to use ~NameOfTheClass like for the constructor, other names are invalid.
Solution 5 - C++
It's the destructor. This method is called when the instance of your class is destroyed:
Stack<int> *stack= new Stack<int>;
//do something
delete stack; //<- destructor is called here;
Solution 6 - C++
That would be the destructor(freeing up any dynamic memory)