Most of the most most basic c---construction data type: Common body

Shared body Definition: The structure of the same memory for different variables

General form: Union Common body Name

{

member table columns

} variable table column;

A common body is also a data type

A reference to a common body: a single member variable reference only

Common features: 1. Common body variables the same memory can be used to hold several different types of members, but only one type at a time. That means that only one member works at a moment.

2. the member that is in effect in the common body variable is the last member to be deposited

3. the address of the shared body variable and the address of its member are the same address

4. You cannot assign a value to a shared body variable name, nor can it be initialized in the definition ;

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Most of the most most basic c---construction data type: Common body