简单字符串连接 [英] Simple string concatenation

问题描述

如果我在Python中有一个字符串 x ='wow'，我可以使用 __ add __ 函数，如下：

  x ='wow'
 x .__ add __（x）
 'wowwow'
  

我如何在C ++中做到这一点？

  
 > std :: string x =wow; 
 x + x; 
  

创建一个临时字符串，它是 x 与 x 的连接并丢弃结果。要附加到 x ，您将执行以下操作：

  std :: string x =wow; 
 x + = x; 
  

注意双引号 ，在C ++中，单引号用于单字符，双引号用于空结尾的字符串文字。

请参阅 std :: string reference。

顺便说一句，在Python中，你通常不会调用 __ add __（）方法。 p>

  x ='wow'
x + x 
  

__ add __（）方法只是为类提供plus运算符的python方法。

If I have a string x='wow' in Python, I can concatenate this string with itself using the __add__ function, like so:

x='wow'  
x.__add__(x)  
'wowwow'

How can I do this in C++?

解决方案

Semantically, the equivalent of your python code would be something like

std::string x = "wow";
x + x;

i.e. create a temporary string which is the concatenation of x with x and throw away the result. To append to x you would do the following:

std::string x = "wow";
x += x;

Note the double quotes ". Unlike python, in C++, single quotes are for single characters, and double-quotes for null terminated string literals.

See this std::string reference.

By the way, in Python you wouldn't usually call the __add__() method. You would use the equivalent syntax to the first C++ example:

x = 'wow'
x + x

The __add__() method is just the python way of providing a "plus" operator for a class.

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