Can a non pointer be null?

Can a non pointer be null?

The short answer is no, you should never assign NULL to a non-pointer variable.

Can we pass null as argument in C++?

NULL is a valid pointer: it points to memory location zero. Therefore you can pass NULL into a function that takes a Book* pointer, because it IS a Book* pointer.

How do you pass a null to a function?

You can pass NULL as a function parameter only if the specific parameter is a pointer. The only practical way is with a pointer for a parameter. However, you can also use a void type for parameters, and then check for null, if not check and cast into ordinary or required type.

How do you pass a null pointer?

b) To check for a null pointer before accessing any pointer variable. By doing so, we can perform error handling in pointer related code e.g. dereference pointer variable only if it’s not NULL. c) To pass a null pointer to a function argument when we don’t want to pass any valid memory address. fun(NULL);

What null means C++?

Null is a built-in constant that has a value of zero. It is the same as the character 0 used to terminate strings in C. Null can also be the value of a pointer, which is the same as zero unless the CPU supports a special bit pattern for a null pointer.

Can we pass null as a parameter?

The Null object is a special instance of a class which represents missing value. If some method expects an object as a parameter, you can always pass the Null object representation without worry it will cause an unexpected exception at the runtime.

Can dereference a null pointer C++?

Dereferencing a null pointer is undefined behavior. On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard.

Should we pass null in function?

Conclusion. Returning null from a function does a lot of harm to the function signature, and makes the function more complex. By moving the null check outside of the function, only the places that have an invalid state anyway have to deal with it, keeping the rest of your code clean.

WHAT IS null pointer give an example?

A null pointer constant is an integer constant expression that evaluates to zero. For example, a null pointer constant can be 0, 0L , or such an expression that can be cast to type (void *)0 . You can specify any of the following values for a null pointer constant: 0.

When a pointer is null?

Here, Null means that the pointer is referring to the 0th memory location. If we do not have any address which is to be assigned to the pointer, then it is known as a null pointer. When a NULL value is assigned to the pointer, then it is considered as a Null pointer.

Does null exist in C?

Null is a built-in constant that has a value of zero. It is the same as the character 0 used to terminate strings in C.

Why can’t I pass Null Arguments to INT parameters?

Yet NULL is by convention used for pointer arguments, not integral arguments. So the compiler warns you that you’re passing a NULL argument to an int parameter. To make things worse, this is technically wrong as that non-const integer 0 argument is no longer guaranteed to be convertable to a null pointer.

What happens when you pass Null as a parameter in Python?

Similar is the case when you pass “NULL” as a parameter. It will not generate any error but pops up a warning message. Below code snippet will help you to understand more clearly, But while working on big projects you should not avoid such warnings. So to fix this warning you should take the formal argument of pointer type.

Is null a value or a pointer?

So if you look closely at the definition then you will notice one thing that, “NULL” is both, value as well as a pointer. You can consider “NULL” as value when you are directly assigning it to a variable at the time of defining a variable.

What is the type of null in template arguments?

Template argument deduction deduced the type of NULL as int (as you can see from the end of the warning). Yet NULL is by convention used for pointer arguments, not integral arguments. So the compiler warns you that you’re passing a NULL argument to an int parameter.