I have summed up, I feel that I can help beginners to see some complicated grammar rules, understand the true meaning of the C language, not necessarily correct, welcome to discuss, correct, supplement
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Any operation that generates numerical results can be used as an expression, and can be placed in any way that requires numerical results, as long as the numerical type can match
Common, calculations and operations that can generate numerical results
Arithmetic, logic, bit operation, etc.: &, *, etc. have a function of return value
Common places where you need a value:
Assignment condition judgment function call
2. Type law
Any type can be used in any of the needs type; use any type-defined variables to take up memory
Known special case
Function return value cannot be defined as an array type
Common type
Basic data type, pointer, array, structure ...
Common needs type
Define variable definitions pointers, arrays, and structural function parameters and return values Sizeof
3. Parameter delivery law
The parameter passes when the function call is always called, and the value of the value is copied.
Conference: Parameters provided by the caller: Function defined parameters Basic data types are unable to quench Struct does not have to check the pointer as a parameter, the contents of the pointer variable (that is the memory address it point to the memory) are used as a copy number. When the parameter is equal, it is equivalent to the pointer.
