toStdString().c_str()[0]
时间: 2024-05-29 12:12:51 浏览: 15
This code converts a QString to a std::string and then returns the first character of the resulting std::string as a const char*.
Explanation:
- toStdString(): This function is a member of the QString class in Qt framework. It converts a QString to a std::string. The return value of toStdString() is a std::string.
- c_str(): This function is a member of the std::string class in C++ standard library. It returns a const char* pointer to the underlying character array of the string.
- [0]: This is an array subscript operator that accesses the first element of the character array, i.e., the first character of the std::string.
So, the entire expression toStdString().c_str()[0] first converts a QString to a std::string and then returns the first character of the string as a const char*. Note that this expression assumes that the QString is not empty. If the QString is empty, then this expression results in undefined behavior.
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