DaniWeb Forum Index > Software Development > C++

string to char

Please support our C++ advertiser: Intel Parallel Studio Home

•

Join Date: Sep 2008

Posts: 16

Reputation: san_sarangkar is an unknown quantity at this point

Solved Threads: 0

san_sarangkar san_sarangkar is offline

Offline

Newbie Poster

string to char

Oct 14th, 2008

Hello guies please help me
how can I typecast string to char

•

Join Date: Aug 2005

Posts: 15,578

Reputation: Ancient Dragon has a reputation beyond repute

Solved Threads: 1486

Ancient Dragon Ancient Dragon is offline

Offline

Still Learning

Re: string to char

Oct 14th, 2008

you can't because you can't stuff a whole string into a single character. If this is about some error message you got, then post the error message along with the code you wrote.

Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.

•

Join Date: Sep 2008

Posts: 15

Reputation: ninwa is an unknown quantity at this point

Solved Threads: 2

ninwa

Offline

Newbie Poster

Re: string to char

Oct 14th, 2008

A string cannot be cast to a char, because a char is one byte and a string can be any number of bytes. You can, however, use std::string's c_str member and create a const char* out of your string.

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
string s = "hi";
const char *cs = s.c_str();
string s = "hi";
const char *cs = s.c_str();

This can be useful if you want to copy the value into a character array, which might look like this:

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
string s ="hello";
char carr[6]; // note the size, leave room for \0
strcpy( carr, s.c_str() );
string s ="hello";
char carr[6]; // note the size, leave room for \0
strcpy( carr, s.c_str() );

Or, if you want to return a single character from a string you can either use the [] operator or the at member.

 Help with Code Tags 
 c++ Syntax (Toggle Plain Text) 
string s = "hello";
cout << s[0]; // prints 'h'
cout << s.at(1); // prints e
string s = "hello";
cout << s[0]; // prints 'h'
cout << s.at(1); // prints e

•

Join Date: Oct 2007

Posts: 305

Reputation: stilllearning has a spectacular aura about

Solved Threads: 43

stilllearning stilllearning is offline

Offline

Posting Whiz

Re: string to char

Oct 14th, 2008

Do you mean string to char* ? You could access the c_str() , which is of type const char*.

•

Join Date: Sep 2008

Posts: 16

Reputation: san_sarangkar is an unknown quantity at this point

Solved Threads: 0

san_sarangkar san_sarangkar is offline

Offline

Newbie Poster

Re: string to char

Oct 14th, 2008

ok , can I typecast string into double?

I want to convert string 12.12 to double 12.12

•

Join Date: Sep 2008

Posts: 15

Reputation: ninwa is an unknown quantity at this point

Solved Threads: 2

ninwa

Offline

Newbie Poster

Re: string to char

Oct 14th, 2008

•

Originally Posted by san_sarangkar

ok , can I typecast string into double?

I want to convert string 12.12 to double 12.12

You can do this using stringstreams, as long as you validate the string first to make sure that it is in-fact a double value, otherwise your program will crash. An explicit cast of string to double is not supported, however.

•

Join Date: Oct 2007

Posts: 305

Reputation: stilllearning has a spectacular aura about

Solved Threads: 43

stilllearning stilllearning is offline

Offline

Posting Whiz

Re: string to char

Oct 14th, 2008

OMG NO !!! You should NEVER typecast a string to a numeric type. Use something like strtod() to convert a char* to a double, or use stringstream, see here

Last edited by stilllearning; Oct 14th, 2008 at 9:44 pm.