A double pointer in C or C++ ...
int ** ppi;
... simply means that ppi is a pointer that points to a pointer that points to an int.
When defining function-parameters, another way of declaring this is ...
int * ppi[];
... which means that ppi is a pointer to an array of pointers that each point to an int, which happens to have the exact same meaning, but it is more telling in terms of what the usefulness of such a double pointer might have.
Think of main() ...
int main (int agrc, char ** argv);
int main (int argc, char * argv[]);
... the two forms have exactly the same meaning, but the second form more clearly says what the design paradigm is, that argv is a pointer to an array of pointers that each point to an array of char, i.e. the arguments of the program's invocation.
void pointer
insert or delete values both side.so use double pointer
Increment or decrement the pointer by the required offset.
When a variable is declared as being a pointer to type void it is known as a generic pointer. Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. It is still a pointer though, to use it you just have to cast it to another kind of pointer first. Hence the term Generic pointer.
The pointer that points to a block of memory that does not exist is called a dazzling pointer or wild pointer
void pointer
is C or D
C
Pointer in C is Memory Reference. It stores memory address of any variable, constant, function or something you later use in your programming. Pointer basically used to ease the referencing of variables and others or in polymorphism and inheritance.
insert or delete values both side.so use double pointer
pointer: to access data by address reference: there is no reference in C language
Pointer is a variable that stores address of a variable . A NULL Pointer a pointer that doesn't point to anything, it is a literal zero .Some people ,notably C++ programmers, prefer to use 0 rather than NULL.
with the help of pointers we able to store the memory location of any variable. In c the pointer variable is use to store the memory location of any variable. The pointer variable is define as a simple variable but in pointer variable use a special "*" character at the left most side of name of pointer variable. If any variable name have * it means it is a pointer variable it hold the memory location of variable.
A pointer looks a bit like a stick. I use it to point at something. Read your text book, read C tutorials on the web and if you still cannot answer the question consider floor sweeping or basket weaving as a vocation.
Increment or decrement the pointer by the required offset.
It is a pointer that points to a member of a structure.
no