定义一个字符串 [英] Define a string

问题描述

我需要将字符串与字符和数字混合，但这些数字是可变的，例如;

char filename [] =" xxx"那么varxxx那么var;

即，filename =" ind23ept12"其中23是var x，12是var y。


int x;

int y;

char filename [20];

cin>> x>> y;

char * filename;

filename = strcpy（filename，" inf_h_"）;

filename = itoa（filename，x）;

filename = strcpy（filename，" _f_"）;

filename = itoa（filename，y）;

myfile.open（" filename"）;

I need to put a filename is mixed from characters and numbers but these numbers are variable, for example;
char filename[]="xxx" then var "xxx" then var;
i.e., filename="ind23ept12 " where 23 is var x and 12 is var y.


int x;
int y;
char filename[20];
cin>>x>>y;
char *filename;
filename=strcpy(filename,"inf_h_");
filename=itoa(filename,x);
filename=strcpy(filename,"_f_");
filename=itoa(filename,y);
myfile.open("filename");

推荐答案

我不知道它在C ++世界中是否运行良好，但对于C，你可以使用sprintf函数。格式与printf函数相同，只是第一个参数是您要写入的字符串。

I don''t know if it plays well in the C++ world, but for C you can use the sprintf function. The format would be the same as the printf function except that the first argument is the string you want to write to.

Sprintf应该在C ++中工作。只需包含c头文件。


C ++解决方案是使用一种叫做ostringstream的东西。它们存在于< sstream>中。头文件。你像cout一样使用它们，然后用str（）提取字符串信息。例如：


ostringstream oss;

oss<< "路径" << 11<< " /文件" << 22.22;

cout<< oss.str（）


将打印出path11 / file22.22

Sprintf should work in C++. Just include the c header file.

The C++ solution is to use something called an ostringstream. They are found in the <sstream> header file. You use them like cout and then extract the string info with str(). For example:

ostringstream oss;
oss << "path" << 11 << "/file" << 22.22;
cout << oss.str()

will print out "path11/file22.22"

当我尝试使用ostringstream oss时;

undecalare ostringstream

When I am trying to use ostringstream oss;
undecalare ostringstream

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