unsigned short int和unsigned short之间的区别

Question

Is there a difference between unsigned short int and a unsigned short decleration in c and if so, what is it please ? I tried looking online, but couldn't find anything worthwhile.

unsigned short int x1;
unsigned short x2;

Lastly, if there is a difference, how can I cast them to each other respectively please?

Answer 1

From C11 [PDF] (irrelevant parts omitted) (emphasis mine):

6.7.2.2:

At least one type specifier shall be given in the declaration specifiers in each declaration, and in the specifier-qualifier list in each struct declaration and type name. Each list of type specifiers shall be one of the following multisets (delimited by commas, when there is more than one multiset per item); the type specifiers may occur in any order, possibly intermixed with the other declaration specifiers.

• ...
• short , signed short , short int , or signed short int
• unsigned short , or unsigned short int
• ...

6.7.2.5:

Each of the comma-separated multisets designates the same type ...

Answer 2

Just using short is a short-hand (no pun intended) way of writing short int . Just a long is a short-hand for long int .

Answer 3

No difference in the both.

The second is considered to be an int and are simply omitted.

Answer 4

They are synonyms. If you're compiler does something different with them, it's broken.

Answer 5

There is no difference. Try the sizeof operator:

main()
{
  unsigned short int x1;
  unsigned short x2;

  printf("%d/%d\n", sizeof x1, sizeof x2);
}