用于评估字符串输入 C++ 的 switch 语句

Question

我正在处理用户输入的字符串输入，我需要使用 switch 语句来评估每个输入的输入。我下面的代码目前评估用户字符串输入，并使用 ASCII 代码查看它是大写字母、数字还是特殊字符。我现在确定 switch 语句的工作原理以及如何将 If 语句更改为 switch 语句。

for (int i = 0; i < strlength; i++) //for loop used to check the rules of the password inputted by the user
{
  cout << "Testing for upper case characters..." << endl; //displays the cout
  tmpi=(int) str1[i]; //stoi function making the string input an integer
  if ((tmpi >= 65) && (tmpi <= 90)) //checks if there are two upper case characters in the string
    {
      cout << "Found an uppercase" << endl;
      uppercnt++; //adds to the counter of upper case
      state++;
      cout << "Now in state q" << state << "..." << endl;
      continue;
    }
  cout << "Testing for digits..." << endl;
  if(tmpi >= 48 && tmpi <= 57) //checks if there are two digits in the string
    {
      cout << "Found a digit" << endl;
      digitcnt++; //adds to the counter of digit
      state++;
      cout << "Now in state q" << state << "..." << endl;
      continue;
    }
  cout << "Testing for special characters..." << endl;
  if(tmpi >= 33 && tmpi <= 47 || tmpi >= 58 && tmpi <= 64 || tmpi >= 91 && tmpi <= 96 || tmpi >= 123 && tmpi <= 126) //checks if there are special characters
    {
      cout << "Found a special char" << endl;
      speccnt++; //adds to the counter of special character
      state++;
      cout << "Now in state q" << state << "..." << endl;
      continue;
    }
  cout << "Character entered was a lower case" << endl;
  state++;
  cout << "Now in state q" << state << "..." << endl;
} //end for loop

任何建议或示例都会有所帮助，谢谢。

Answer 1

如果性能不是问题，我会使用std::count_if：

int upps = std::count_if( pass.begin(), pass.end(), isupper );
int digs = std::count_if( pass.begin(), pass.end(), isdigit );

ideone 上的工作示例