Question

我正在制作这个小程序。在lamens术语中，我想要制作一个用户可以输入他的选择的菜单，它将他带到预定区域，并且在他完成之后将他带回菜单，在那里他可以做出不同的选择。当你按下1时，我已经显示它显示的位置（你会看到我对代码的意思）。但是在经历了它应该做的事情之后，它不会回到菜单，只是继续第二个选项。还要说你在菜单上，你想从第一个选项开始第二个选项。任何人都可以帮助我...

#include <iostream>

using namespace std;

int main()
{
int option;

    cout << "Hello there...\n\nToday we are going to do a little fun project that I created.\n\n";
    cin.get();

    cout << "\nAs we progress throughout this program, I will explain the different things\n";
    cout << "that we are going to do. We will be covering some basic C++ excersises.";
    cout << "\n\nFirst and foremost we will  begin by  covering what I have learned so far....\n\n";
    cin.get();

    cout << "The first topic we will cover will include what is known as 'variables'.\n";
    cout << "what are variables you ask?";
    cin.get();


    int var = 1;
    int main=1;
        do
        {
            cout << "\n\n\nEnter the number of one of the following and I will explain!\n";
            cout << "1.integer  2.boolian   3.floats   4.doubles   5.character";
            cout << "\n\n[when you are done type 'done' to continue]\n\n";
            cin >> option; //this is where the user puts in his option (1,2,3,4,5,6) I have only 1 and 2 complete

            if (option = 1) //starts with this regardless of input
            {
                cin.ignore();
                cout << "\n\n\nInteger is the variable abbreviated as 'int' this allows C++ to only";
                cout << "\nread whole and real numbers. C++ takes this number as stores it\n";
                cout << "in a user-defined variable (you can make up what that variable is..)\n";
                cin.get();
                cout << "an example syntax would be:";
                cout << "\n\nint var=[whole;real number]";
                cin.get();
                cout << "\n\nwhat this implies is that you have 'declared' to the system";
                cout << "\nthat you are going to use an 'int' that you have named 'var'\n";
                cout << "and in this 'var' you are going to store a real and whole number\ninside of it.";
                cout << "\n\nPress any key to go back to menu";
                cin.get();
            }
            else if (option = 2); //continues with this without going back to menu.
            {
                cin.ignore();
                cout << "\n\n\nBoolian is the variable abbreviated as 'bool' this allows C++ to only";
                cout << "\nread true or false ( 0 or 1 ). C++ takes this number as stores it\n";
                cout << "in a user-defined variable (you can make up what that variable is..)\n";
                cin.get();
                cout << "an example syntax would be:";
                cout << "\n\nbool var=[true or false]";
                cin.get();
                cout << "\n\nwhat this implies is that you have 'declared' to the system";
                cout << "\nthat you are going to use an 'bool' variable that you have named 'var'\n";
                cout << "and in this 'var' you are going to store a either a true or false\ninside of it.";
                cout << "\n\nPress any key to go back to menu";
                cin.get();
            }

        } while (var = 1);

}

Answer 1

问题在于比较运算符

1）if (option = 1)，使用if(option == 1)

2）else if (option = 2);，使用else if(option == 2)，删除分号

3）while(var = 1) ;，使用while(var ==1 );

Answer 2

C ++中的比较是使用==运算符完成的： e。

 if (option == 1) 
 if (option == 2) 
 while (var == 1);

菜单结构和循环

2 个答案: