从函数获取输入-C ++ [英] Getting Input from a Function - c++

问题描述

我在c ++中遇到了一个问题，我调用了一个为事物分配一些值的函数，但是在函数完成后这些分配会丢失.这是我的代码:

I've been having a problem in c++ where I call a function which assigns some values to things, but those assignments are lost after the function has been completed. Here is my code:

#include <iostream>
#include <string>

using namespace std;

void Input(string a, string b){

    cout << "Input a: \n";
    cin >> a;
    cout << endl;

    cout << "Input b: \n";
    cin >> b;
    cout << endl << "Inputen Strings (still in the called function): \n";
    cout << a << " " << b << endl << endl;
};

int main(){
    string c = "This didn't";
    string d = "work";

    Input(c,d);

    cout << "Inputen Strings (now in the main function): \n";
    cout << c + " " + d << endl;

    return 0;
};

因此，每当我运行它时(先输入"Hello"，然后输入"World")，程序将按以下方式运行:

So that whenever I run it, (inputting "Hello" and then "World") the program runs as follows:

输入一个:

你好

输入b:

世界

输入字符串(仍在调用的函数中):

Inputen Strings (still in the called function):

Hello World

Hello World

输入字符串(现在在主函数中):

Inputen Strings (now in the main function):

这不起作用

我不知道为什么它只是暂时保存值.感谢您的帮助！

I don't know why it's only temporarily saving the values. Any help is appreciated!

推荐答案

更改方法签名以接受变量&"的地址

change your method signature to accept the address of the variables "&"

void Input(string &a, string &b)

不带&"运算符，您只是将变量的副本发送到函数中，并带有&"地址运算符，您正在通过引用传递变量

without the "&" operator you are just sending copy's of the variable into the function, with the "&" address-of operator you are passing the variables by reference

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