Lvalues and Rvalues in C#

一般左值既可以在表达式的左边也可以在右边；

但是右值只能在表达式的右边；

例如：

a = 10;   正确

a=b+10;正确

10 =11； 错误

英文解释如下：

There are two kinds of expressions in C#:

1. lvalue: An expression that is an lvalue may appear as either the left-hand or right-hand side of an assignment.

2. rvalue: An expression that is an rvalue may appear on the right- but not left-hand side of an assignment.