如何將ascii轉換為unsigned int

Question

有沒有將字符串轉換為unsigned int的方法？ _ultoa存在但無法找到vise版本...

Answer 1

std::strtoul()是其中之一。 然后又有像atoi()這樣的舊版本。

Answer 2

Boost提供lexical_cast。

#include <boost/lexical_cast.hpp>
[...]
unsigned int x = boost::lexical_cast<unsigned int>(strVal);

或者，你可以使用stringstream（這基本上是lexical_cast在幕后的內容）：

#include <sstream>
[...]
std::stringstream s(strVal);
unsigned int x;
s >> x;

Answer 3

sscanf會做你想要的。

char* myString = "123";  // Declare a string (c-style)
unsigned int myNumber;   // a number, where the answer will go.

sscanf(myString, "%u", &myNumber);  // Parse the String into the Number

printf("The number I got was %u\n", myNumber);  // Show the number, hopefully 123

Answer 4

如果你通過_atoi64去了它

unsigned long l = _atoi64（str）;

Answer 5

int atoi （const char * str）怎么樣？

string s("123");
unsigned u = (unsigned)atoi(s.c_str());