Long int (int can be omitted) declares a relatively long integer variable (generally used to store a large number of integer variables).

Int declares an integer variable between short and long.

Unsigned int declares an Unsigned int variable (unsigned is 0 and integer).

Unsigned Long Declares an unsigned long variable.

Unsigned short integer Declares an unsigned short integer variable.

1 to determine the memory space occupied by the variable.

Take the general 16-bit computer as an example:

Short and int account for 2 bytes, namely 16bit. 0000 0000 0000 0000

Long occupies 4 bytes, or 32 bits. 0000 0000 0000 0000 0000 0000 0000 0000

Unsigned occupies the same space as its same type. For example:

An unsigned long integer occupies 4 bytes.

2. Determine whether the first position in the occupied space represents a number or a symbol.