Day 1：Introduction

阅读更多

1.1 Why use a language like C++

1.  
   1. Conciseness
   2. Maintainability
   3. Portability

1.2 The compilation process

         sorce file>>>Prcessed code>>>Object file

 

1.3 General notes on C++

 

             case sensitive

2.1 hello world

/* 
 * File:   main.cpp
 * Author: Gong Li
 *
 * Created on June 24, 2011, 9:18 PM
 */

#include 

using namespace std;

/*
 * 
 */
int main() {
    std::cout<<"Hello,world!";
    return 0;
}

 
2.2 Tokens

            keywords, identifiers,literals, operators, punctuation, whitespace

 

2.3 Explaination

 

• comment:           //.... or /*....*/
• #include:           the preprocessor dumping in the content of another file.
• int main(){}:     execute when the program starts up
• cout <<:            outputting some piece of text
• namespaces:    like std includes a group of idemntifiers
• strings:             Hello, world!
• escape sequence: \b  \n...
• return 0:           tell the OS it has completed successfully

 

3 Input

      Input  cin >> x
    

     Output cout << "hello"