Simple quiz on cpp

Let us see whether you can answer this memory allocation question on c++

To allocate memory for an integer in c++, you can use

1. int *ptr = new int;
2. int *ptr = new int(10);
3. int a=12; int *ptr = new int(a+2);
4. any of these

Answer : 4

All of these are valid methods of dynamic memory allocation in c++. 

• First line allocates memory for an integer and the address of this integer is stored in ptr
• Second line allocates memory for an integer and initializes this integer to 10. *ptr = 10
• Third line allocates memory for an integer and initializes that integer to 12

Also note that


    int *ptr =new int[10]; 

is completely different, which allocate memory for an array of 10 integers.