从c ++中的文件读取整行 [英] Reading a whole line from file in c++

问题描述

我正在使用c ++中的程序，我需要从文件中读取整个文本字符串。该文件包含一行上的地址，像这样123 Easy Ave，这必须拉入一个字符串或字符。这是我的代码：

I am working on a program in c++ and I need to read an entire string of text from a file. The file contains an address on one of the lines like this "123 Easy Ave" this has to be pulled into one string or char. Here is the code I have:

数据文件：

Matt Harrold
307C Meshel Hall
1000 .01 4

最后一行是要填充地址的地址，然后是三个数字：principle，InterestRate，Years。

The data is made up of a first and last name which become CustomerName, the next line is the address which is to populate Address, Then three numbers: principle, InterestRate, Years.

代码：

float InterestRate = 0;
int Years = 0;
char Junk [20];
int FutureValue;
float OnePlusInterestRate;
int YearNumber;
int count = 0;
char CustomerName;
string Address;
int * YearsPointer;


       CustomerFile >> CustomerName
                >> Address
                >> Principle
                >> InterestRate
                >> Years;

现在它只会拉入103C并停在空间...帮助非常感谢！

Right now it only pulls in "103C" and stops at the space... Help is greatly appreciated!

推荐答案

编辑：为了回应对我问题的反馈，我编辑它使用更合适的 std :: getline 而不是 std :: istream :: getline 。这两个都足够了，但 std :: getline 更适合 std :: string

In response to feedback on my question, I have edited it to use the more appropriate std::getline instead of std::istream::getline. Both of these would suffice, but std::getline is better suited for std::strings and you don't have to worry about specifying the string size.

使用 std :: getline（）从< string> 。

这里有一个很好的参考和例子： http://www.cplusplus.com/reference/string/getline/ 。

There is a good reference and example here: http://www.cplusplus.com/reference/string/getline/.

您还需要小心地组合提取（>> ）运算符和 getline 。此问题的最高答案（ cin>>不适用于getline（））简要解释为什么它们不应该一起使用。简而言之，调用 cin>> （或您使用的任何输入流）在流中留下换行符，然后由 getline ，给你一个空字符串。如果你真的想一起使用它们，你必须在两个调用之间调用 std :: istream :: ignore 。

You'll also need to be careful combining the extraction (>>) operator and getline. The top answer to this question (cin>> not work with getline()) explains briefly why they shouldn't be used together. In short, a call to cin >> (or whatever input stream you are using) leaves a newline in the stream, which is then picked up by getline, giving you an empty string. If you really want to use them together, you have to call std::istream::ignore in between the two calls.

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