将字符串转换为整数 [英] Converting string to integer
问题描述
我有一个字符串:
string A =" 2";
我需要得到它的整数值:
// ??
int val = A; // ??
>我有一个字符串:
字符串A =" 2" ;;
我需要得到它的整数值:
// ??
int val = A; // ??
假设你包含stdlib.h并且string-class为const char提供了
cast-operator *:
int val = atoi(string);
" Gil" <峰; br ************** @ hotmail.com>在消息中写道
新闻:ad ************************* @ posting.google.co m ... < blockquote class =post_quotes>我有一个字符串:
字符串A =" 2" ;;
我需要得到它的整数值:
查看 http://www.groups。 google.com
无论如何,
int main()
{
string str =" 123";
istringstream iss(str);
int x;
iss>> x;
if(iss)
{
//转换成功
}
else
{
//无法将str转换为int
}
}
祝福,
Sharad
" Patrik Stellmann" < ST ******* @ tu-harburg.de>在消息中写道
news:bv ************ @ uni-berlin.de ...我有一个字符串:
字符串A =" 2" ;;
我需要得到它的整数值:
/ / ??
int val = A; // ??假设你包含stdlib.h并且string-class为const char提供了
cast-operator *:
抱歉,这两个假设都是错误的。
包含的标准标题是< cstdlib>如今。此外,字符串类不提供
隐式const char *转换,而是提供c_str()成员函数。
int val = atoi(string);
int val = atoi(A.c_str());
应该可以解决问题。
问候
Chris
I have a string :
string A = "2";
I need to get it''s integer value :
// ??
int val = A ; // ??
> I have a string :
string A = "2";
I need to get it''s integer value :
// ??
int val = A ; // ??
assuming you include stdlib.h and the string-class provides the
cast-operator to const char*:
int val = atoi(string);
"Gil" <br**************@hotmail.com> wrote in message
news:ad*************************@posting.google.co m...I have a string :
string A = "2";
I need to get it''s integer value :
Check http://www.groups.google.com
Anyways,
int main()
{
string str = "123";
istringstream iss(str);
int x;
iss >> x;
if(iss)
{
// conversion successful
}
else
{
// could not convert str to an int
}
}
Best wishes,
Sharad
"Patrik Stellmann" <st*******@tu-harburg.de> wrote in message
news:bv************@uni-berlin.de...I have a string :
string A = "2";
I need to get it''s integer value :
// ??
int val = A ; // ?? assuming you include stdlib.h and the string-class provides the
cast-operator to const char*:
Sorry, but both of these assumptions are incorrect. The standard header to
include is <cstdlib> nowadays. Furthermore the string class does not provide
an implicit const char* conversion but rather the c_str() member function.
int val = atoi(string);
int val = atoi( A.c_str() );
should do the trick.
Regards
Chris
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