C Review 2

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The basic concepts of operators and expressions in C.

1. Data Object: it refers to the term of the data storage area (the storage area used to save variables or arrays is a data object );

2. Lvalue: used to identify the name or expression of a specific data object. Because not all data objects can be modified, therefore, "modifiable left value" is used to indicate objects that can be changed. Therefore, the left side of the value assignment operator should be a modifiable left value (for example, the const type cannot be modified );

3. Right Value: (Rvalue): indicates the amount that can be assigned to the left value that can be modified;

4. C99 requires the integer division to follow the principle of "toward Zero truncation", that is,-3.8 is written as-3;

5. When an expression appears, the signed and unsigned short and char types are automatically converted to int, And the unsigned int and float types are converted to double as needed, these transformations are called ascension;
   

6. In any operation that contains two data types, both values are converted to a higher level;