Set - 4

Question 11 :

Anything wrong with this code?

T *p = new T[10]; 
delete p;

 

Answer :

Everything is correct, Only the first element of the array will be deleted", The entire array will be deleted, but only the first element destructor will be called.


Question 12 :

Anything wrong with this code?

T *p = 0;
delete p;

 

Answer :

Yes, the program will crash in an attempt to delete a null pointer.


Question 13 :

How do you decide which integer type to use?

Answer :

It depends on our requirement. When we are required an integer to be stored in 1 byte (means less than or equal to 255) we use short int, for 2 bytes we use int, for 8 bytes we use long int. 

A char is for 1-byte integers, a short is for 2-byte integers, an int is generally a 2-byte or 4-byte integer (though not necessarily), a long is a 4-byte integer, and a long long is a 8-byte integer.


Question 14 :

What does extern mean in a function declaration?

Answer :

Using extern in a function declaration we can make a function such that it can used outside the file in which it is defined. 

An extern variable, function definition, or declaration also makes the described variable or function usable by the succeeding part of the current source file. This declaration does not replace the definition. The declaration is used to describe the variable that is externally defined. 

If a declaration for an identifier already exists at file scope, any extern declaration of the same identifier found within a block refers to that same object. If no other declaration for the identifier exists at file scope, the identifier has external linkage.


Question 15 :

What can I safely assume about the initial values of variables which are not explicitly initialized?

Answer :

It depends on complier which may assign any garbage value to a variable if it is not initialized.