cannot convert 'std::string'
时间: 2023-10-16 20:07:46 浏览: 66
这个错误通常出现在你试图将一个字符串类型转换成其他类型时,但是转换失败了。可能原因是你的字符串格式不正确,或者你的代码逻辑有误。
例如,在使用 stod 函数将字符串转换为 double 类型时,如果字符串不是有效的数字格式,就会出现这个错误。你需要检查字符串是否符合要求,或者使用其他方法进行转换。另外,请确保你包含了正确的头文件,如 <string> 或 <iostream>。
相关问题
[Error] cannot convert 'std::string {aka std::basic_string<char>
这个错误是因为你将`std::string`类型转换为`char*`类型时发生了类型不匹配的错误。你可以通过以下两种方法来解决这个问题。
方法一:使用`c_str()`函数
你可以使用`c_str()`函数将`std::string`类型转换为`const char*`类型,然后将其传递给函数。这样可以避免类型不匹配的错误。
举个例子:
```cpp
void str(const char* ss) {
cout << ss;
}
int main() {
string s;
getline(cin, s);
str(s.c_str());
return 0;
}
```
方法二:使用`string`类型作为函数参数
你也可以直接将`std::string`类型作为函数的参数,而不是使用`char*`类型。
举个例子:
```cpp
void str(string ss) {
cout << ss;
}
int main() {
string s;
getline(cin, s);
str(s);
return 0;
}
```
这两种方法都可以解决你遇到的类型不匹配的问题。你可以根据具体的需求选择其中一种方法来修改你的代码。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
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[ .reference_list ]
[Error] cannot convert 'std::string {aka std::basic_string<char>}' to 'char*' in assignment
This error occurs when you try to assign a `std::string` object to a `char*` variable.
The problem is that `std::string` is a class that represents a string of characters and is not the same as a C-style string (i.e., a `char*` array). Therefore, you cannot assign a `std::string` directly to a `char*` variable.
To fix this error, you can either:
1. Use the `c_str()` method of `std::string` to obtain a pointer to a null-terminated character array that can be assigned to a `char*` variable. For example:
```
std::string str = "hello";
char* cstr = str.c_str();
```
2. Use a `std::vector<char>` instead of a `char*` to store the string. For example:
```
std::string str = "hello";
std::vector<char> vec(str.begin(), str.end());
```