What happens if we print null pointer?

What happens if we print null pointer?

The C standard makes it undefined to pass anything other than a pointer to a null-terminated string as second argument to printf(“\%s”, . These developers are relying on the kindness of the underlying libc implementation. …

Can you print pointers in C?

Printing pointers. You can print a pointer value using printf with the \%p format specifier. To do so, you should convert the pointer to type void * first using a cast (see below for void * pointers), although on machines that don’t have different representations for different pointer types, this may not be necessary.

How do I print a pointer address?

To print the address of a variable, we use “\%p” specifier in C programming language. There are two ways to get the address of the variable: By using “address of” (&) operator. By using pointer variable.

How do I print a pointer address without printf?

If you want to print the value of a pointer without using the format \%p specifier, you can cast the pointer to an integer that has the same size and then print the integer value. int x; Serial. println (&x, HEX);

When null pointer is used in C?

A null pointer is a pointer which points nothing. Some uses of the null pointer are: a) To initialize a pointer variable when that pointer variable isn’t assigned any valid memory address yet. b) To pass a null pointer to a function argument when we don’t want to pass any valid memory address.

Can you print null character in C?

In short: \%c means to print a character, so printf print the NUL character which value is 0. NUL is a non-printing characters. “Hello\0, world” is a string literal, the result of strlen(“Hello\0, world”) is 5. So printf will print the result “Hello”.

How do I print a char pointer?

“c printing char pointer” Code Answer

1. #include
2. int main()
3. {
4. char * str = “Hello”;
5. printf(“\%s\n”, str);
6. return 0;
7. }

What is the address of a pointer in C?

A pointer is a variable that stores the address of another variable. Unlike other variables that hold values of a certain type, pointer holds the address of a variable. For example, an integer variable holds (or you can say stores) an integer value, however an integer pointer holds the address of a integer variable.

Why do C++ and C have undefined behaviors?

C and C++ have undefined behaviors because it allows compilers to avoid lots of checks. Suppose a set of code with greater performing array need not keep a look at the bounds, which avoid the needs for complex optimization pass to check such conditions outside…

How to print the address of a pointer variable?

If you use the \%u or \%x (or anything other than \%p) to attempt to print an address, it might appear If you need to print an address of something, or the contents of a pointer variable, the only truly portable way to do it is to use the \%p format specifier.

Why can’t I print an address with \%u or \%X?

If you use the \%u or \%x (or anything other than \%p) to attempt to print an address, it might appear to work in some environments, but will actually be undefined behavior and non-portable. You can’t assume that the size of a pointer is the same as the size of an unsigned integer (or any other integer data type).

What is the difference between \%P and \%U in C++?

The \%p conversion prints a pointer in an implementation specific way. The \%u and \%x conversions are for unsigned int or int types, which may or may not be the same size as a pointer type. The \%u conversion prints an unsigned decimal integer, while \%x prints an unsigned hexadecimal integer in lower case.