C++ 如何比较字符串

How to compare strings

提问by Anon

I wanted to compare a string without actually defining one of them as a string, something like this,

我想比较一个字符串而不实际将其中一个定义为一个字符串，就像这样，

if (string == "add")

Do I have to declare "add"as a string or is it possible to compare in a similar way?

我必须声明"add"为字符串还是可以以类似的方式进行比较？

回答by e.James

In C++ the std::string class implements the comparison operators, so you can perform the comparison using ==just as you would expect:

在 C++ 中， std::string 类实现了比较运算符，因此您可以按照==预期使用以下方法执行比较：

if (string == "add") { ... }

When used properly, operator overloadingis an excellent C++ feature.

如果使用得当，运算符重载是一个出色的 C++ 特性。

回答by Christopher Armstrong

You need to use strcmp.

您需要使用strcmp.

if (strcmp(string,"add") == 0){
    print("success!");
}

回答by Algorithmist

You could use strcmp():

你可以使用strcmp()：

/* strcmp example */
#include <stdio.h>
#include <string.h>

int main ()
{
  char szKey[] = "apple";
  char szInput[80];
  do {
     printf ("Guess my favourite fruit? ");
     gets (szInput);
  } while (strcmp (szKey,szInput) != 0);
  puts ("Correct answer!");
  return 0;
}