（１０分）講解一下L-Value 同 r-Value

In general, l-value is an expression that you can put on the left side of the assignment operator (=). All l-values have an assigned memory that is addressable by the user. These include pointers, variables of all types, structures, etc.
For example,
double a,b,c;
char *d;
char list[23];
a,b,c,d and list are all l-values.

Right values are expressions that do not occupy a memory space, and hence cannot be put on the left of the assignment operator.
Examples are: i++, a+b, *d etc.

Hope this answers your question.