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Conversion from Char* to int ?

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Conversion from Char* to int ?

 
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  #1
Jul 19th, 2007
Hi All,

I want to convert char * to int.

Plz help me out.

Thanks in advance.
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Re: Conversion from Char* to int ?

 
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  #2
Jul 19th, 2007
What exactly do you mean?
Do you
a) want to convert an array of ASCII characters into an int:

C++ Syntax (Toggle Plain Text) 
  1. char *numstr = "1234";
  2. int val = atoi(numstr);    // val now = 1234

b) convert the pointer to an int:
C++ Syntax (Toggle Plain Text) 
  1. char *xyz;   // given contents somewhere
  2. int addr = (int)xyz;   // addr now = the char pointer
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Re: Conversion from Char* to int ?

 
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  #3
Jul 19th, 2007
Thanks a lot for your Rply..i will be using atoi().
And it worked for me.
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Re: Conversion from Char* to int ?

 
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  #4
Jul 19th, 2007
Don't use atoi() - here's how to do it in C++
CPP Syntax (Toggle Plain Text) 
  1. #include <sstream>
  2. #include <iostream>
  3.  
  4. int main()
  5. {
  6.     const char* foo("1234");
  7.     std::stringstream ss(foo);
  8.     int i;
  9.     if( ss >> i )
  10.         std::cout << "i is: " << i ;
  11.     else
  12.         std::cout << "error";
  13. }
The reason for using stringstreams is that your conversion will fail if the string contains anything which can't be converted to an int - which, if you're dealing with user input, is a real problem. if you use a stringstream, you can detect the error, without it messing up the rest of the program.
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Re: Conversion from Char* to int ?

 
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Jul 19th, 2007
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Don't use atoi()
Why?
The truth does not change according to our ability to stomach it.
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Re: Conversion from Char* to int ?

 
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  #6
Jul 19th, 2007
I suppose I should add that atoi() has no reliable way of handling any errors that might be thrown up when your conversion fails. This is where stringstreams provide a far more robust solution, that you can test for failure before using the retrieved value.
Last edited by Bench; Jul 19th, 2007 at 9:59 am.
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Re: Conversion from Char* to int ?

 
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  #7
Jul 19th, 2007
> Why?
Answer.
I don't accept change; I don't deserve to live.
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