C++| Ingenious work from 0 to 1 introductory programming [video + courseware + notes + source code]
table of Contents
C++ course schedule
Clarify the learning stage and content of the C++ course
stage content aims Case study The first stage Introduction to C++ Basic Syntax Have a basic understanding of C++ and have basic programming skills Address Book Management System second stage C++ core programming Introduce C++ object-oriented programming to pave the way for large-scale projects Staff Management System The third phase C++ improves programming Introduce C++ generic programming ideas and the basic use of STL Speech contest system
Comprehensive case: computer room reservation system
1 Introduction to C++
1.1 The first C++ program
Writing a C++ program is divided into 4 steps:
Create project
Create a file
Write code
Run the program
1.1.1 Create Project
Visual Studio is the main tool we use to write C++ programs. Let's open it first.
1.1.2 Create file
Right-click the source file and select Add->New Item:
Give the C++ file a name and click Add.
1.1.3 Writing code
#include <iostream>
using namespace std;
int main1()
{
cout << "Hello world ！" << endl;
system("pause");
return 0;
}1.1.4 Run the program
1.2 Notes
Function : Add some explanations and explanations to the code, so that you or other programmers can read the code.
Two formats
- Single line comment :
// 描述信息
- It is usually placed at the top of a line of code or at the end of a statement to describe the line of code.
- Multi-line comments :
/* 描述信息 */
- It is usually placed above a piece of code to give an overall description of the piece of code.
Tip: When the compiler compiles the code, it ignores the content of the comment.
1.3 Variables
Function : Give a name to a specified memory space to facilitate the operation of this memory.
Syntax :
数据类型 变量名 = 初始值;
Example:
Note: When C++ creates a variable, you must give the variable an initial value, otherwise an error will be reported!
1.4 Constant
Function : Used to record the unchangeable data in the program.
C++ defines constants in two ways:
#define macro constants:
#define 常量名 常量值
It is usually defined at the top of the file and represents a constant.
const modified variable:
const 数据类型 常量名 = 常量值
The keyword const is usually added before the variable definition to modify the variable as a constant and cannot be modified.
#define macro constant
Example:
const modified variable
Constant demo code
/*
作用：用于记录程序中不可更改的数据。
C++定义常量两种方式
1.#define 宏常量：#define 常量名 常量值
通常在文件上方定义，表示一个常量
2.const 修饰的变量 :const 数据类型 常量名 = 常量值
通常在变量定义前加关键字，修饰该变量为常量，不可修改
*/
#include <iostream>
using namespace std;
//1、宏常量
#define Day 7
int main4()
{
//day = 14; //报错（错误），Day是常量，宏常量day不可以修改，一旦修改就会报错！
cout << "一周里总共有 " << Day << " 天" << endl;
//2、const修饰变量
const int month = 12;
//month = 24; //报错（错误），常量是不可以修改的。const修饰的变量也称为常量！
cout << "一年里总共有 " << month << " 个月份" << endl;
system("pause");
return 0;
}1.5 Keywords
Function: Keywords are pre-reserved words (identifiers) in C++.
When defining variables or constants, do not use keywords.
C++ keywords are as follows:
asm do if return typedef auto double inline short typeid bool dynamic_cast int signed typename break else long sizeof union case enum mutable static unsigned catch explicit namespace static_cast using char export new struct virtual class external operator switch void const false private template volatile const_cast float protected this wchar_t continue for public throw while default friend register true delete goto reinterpret_cast try
提示：在给变量或者常量起名称时候，不要用C++得关键字，否则会产生歧义。
1.6 Identifier naming rules
Function : C++ stipulates that it has its own set of rules when naming identifiers (variables, constants).
Identifiers cannot be keywords.
The identifier can only consist of letters, numbers, and underscores.
The first character must be a letter or underscore.
The letters in the identifier are case sensitive.
Suggestion: When naming an identifier, strive to achieve the effect of knowing the meaning of the name and making it easier for yourself and others to read.
#include <iostream>
using namespace std;
//标识符命名规则
//1、标识符不可以是关键字
//2、标识符是由字母、数字、下划线构成
//3、标识符第一个字符只能是字母或下划线
//4、标识符是区分大小写的
int main()
{
//1、标识符不可以是关键字
//int int = 10; // 报错
//2、标识符是由字母、数字、下划线构成
int abc = 10;
int _abc = 20;
int _123abc = 30;
//3、标识符第一个字符只能是字母或下划线
//int 123abc = 40; // 报错
//4、标识符是区分大小写的
int aaa = 100;
//cout << AAA << endl; // AAA和aaa不是同一个名称
//建议：给变量起名的时候，最好能够做到见名知意。
int num1 = 10;
int num2 = 20;
int sum = num1 + num2;
cout << sum << endl;
system("pause");
return 0;
}Come on~