How to analyze the similarities and differences between the left and right values of C++

This article will explain in detail how to analyze the common and different points between the left value and the right value of C++. The content of the article is of high quality. Therefore, Xiaobian shares it with you as a reference. I hope that after reading this article, you will have a certain understanding of relevant knowledge.

C++ programming language has many differences compared to C language, and these different places all reflect a very important role.

1. C++ L-Value and R-Value Concepts

Variables and literal constants both have storage areas and have associated types, the difference being that variables are addressable;

For each variable, there are 2 values associated with it:

1> Data value, stored in a memory address, also known as rvalue, rvalue is the read value, literal constants and variables can be used for rvalue.

2> The address value, i.e. the memory address where the data value is stored, is also called the lvalue, and literal constants cannot be used as lvalues.

2 . C++ L-Value and R-Value Related Problems

Parenthesize an expression: ++a--

Result ++(a--)

This expression is illegal because the preincrement operation requires a modifiable lvalue and "a--" is not an lvalue (i.e., an rvalue).

3 . C++ L-value and R-value in the difference between the former increment and the latter increment

In early C textbooks, the for loop statement was usually written as:

for(int i=0;i