是否针对字符串检查argv []？ （C ++） [英] Checking argv[] against a string? (C++)

问题描述

因此，我试图检查要输入到程序中的参数，其中之一是单词 yes或 no，输入时不带引号。

So I'm attempting to check the arguments that I'm inputting into my program, and one of them is either the word "yes" or "no", entered without the quotes.

我正在测试等效性（if（argv [n] == yes）），但每次输入时，它似乎都返回false，实际上，是的（当我输出时，它确认了这一点）。我在这里想念我做错了什么？
如果我正确理解argv [n]返回的字符串以null终止，那么它应该允许我这样做。

I'm trying to test equivalency ( if (argv[n] == "yes") ) but that seems to be returning false every time when the input is, in fact, yes(When I output it it confirms this). What am I missing here that I'm doing improperly? If I understand properly argv[n] returns a cstring that is null-terminated, so it should allow me to do this.

推荐答案

您正在比较指针。使用strcmp或std :: string。

You're comparing pointers. Use strcmp, or std::string.

int main(int argc, char * argv[]) {

  if (argv[1] == "yes"); // Wrong, compares two pointers
  if (strcmp(argv[1], "yes") == 0); // This compares what the pointers point to
  if (std::string(argv[1]) == "yes"); // Works fine
  if (argv[1] == std::string("yes")); // Works fine

  // Easy-mode    
  std::vector<std::string> args(argv, argv+argc);
  for (size_t i = 1; i < args.size(); ++i) {
      if (args[i] == "yes") {
          // do something
      }
  }

}

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