Common (Consortium)

Shared body （ union ）

The difference with the structure is that the address of the common body is the same , Only one member can be used at a time , The space occupied by the community is greater than or equal to the largest data structure in the member . Initialization can only initialize one .

union  name {
    
	 member 1;
	 member 2;
	 member 3;
	...

}

Enumeration type

Statement

enum day{
    monday,tuesday,wednesday,thursday,friday,saturday,sunday};// This is an enumeration constant 
enum day today;// This is an enumeration variable 
today = monday;// Assign a value to a variable 

The data type corresponding to the enumeration constant is int The default from the 0 Start , Add one... In turn , You can customize , For example, put Monday The assignment is 10, Add one after the other , If the Wednesday The assignment is 10, Then the first two are 0,1, And then 10, Add one... In turn .