help3.cpp

这个是个C++WANCHEN的类 在原来的help2的基础上添加了很多功 能 十分强大

/*  
   Project 3-3  
  
   The finished Help system that process multiple requests.  
*/  
  
#include <iostream>  
using namespace std;  
   
int main() {  
  char choice;  
  
  for(;;) {  
    do {  
      cout << "Help on:\n";  
      cout << "  1. if\n";  
      cout << "  2. switch\n";  
      cout << "  3. for\n";  
      cout << "  4. while\n";  
      cout << "  5. do-while\n";  
      cout << "  6. break\n";  
      cout << "  7. continue\n";  
      cout << "  8. goto\n";  
      cout << "Choose one (q to quit): ";  
      cin >> choice;  
      } while( choice < '1' || choice > '8' && choice != 'q');  
  
    if(choice == 'q') break;  
  
    cout << "\n\n";  
   
    switch(choice) {  
      case '1':  
        cout << "The if:\n\n";  
        cout << "if(condition) statement;\n";  
        cout << "else statement;\n";  
        break;  
      case '2':  
        cout << "The switch:\n\n";  
        cout << "switch(expression) {\n";  
        cout << "  case constant:\n";  
        cout << "    statement sequence\n";  
        cout << "    break;\n";  
        cout << "  // ...\n";  
        cout << "}\n";  
        break;  
      case '3':  
        cout << "The for:\n\n";  
        cout << "for(init; condition; iteration)";  
        cout << " statement;\n";  
        break;  
      case '4':  
        cout << "The while:\n\n";  
        cout << "while(condition) statement;\n";  
        break;  
      case '5':  
        cout << "The do-while:\n\n";  
        cout << "do {\n";  
        cout << "  statement;\n";  
        cout << "} while (condition);\n";  
        break;  
      case '6':  
        cout << "The break:\n\n";  
        cout << "break;\n";  
        break;  
      case '7':  
        cout << "The continue:\n\n";  
        cout << "continue;\n";  
        break;  
      case '8':  
        cout << "The goto:\n\n";  
        cout << "goto label;\n";  
        break;  
    }  
    cout << "\n";  
  }  
  
  return 0;  
}