Using atoi() C function to convert a string to integer


Compiler: Visual C++ Express Edition 2005

Compiled on Platform: Windows 2003 Server Standard Edition

Header file: Standard

Additional library: none/default

Additional project setting: Set project to be compiled as C

Project -> your_project_name Properties -> Configuration Properties -> C/C++ -> Advanced -> Compiled As: Compiled as C Code (/TC)

Other info:

To do: Converting a string to an integer value using atoi() C function

To show: How to use atoi() C function in converting a given string to an integer




// Using atoi()_atoi64()/_wtoi()/_wtoi64() - converting string to integer

#include <stdio.h>


int main(void)


int i;

i = atoi("1234");


printf("Using atoi() - converting string to integer\n");


printf("The string \"1234\" converted to int is %d\n", i);

printf("The converted value %d minus 123 is %d\n", i, i - 123);


return 0;



Output example:


Using atoi() - converting string to integer


The string "1234" converted to int is 1234

The converted value 1234 minus 123 is 1111

Press any key to continue . . .



C and C++ Programming Resources | C & C++ Code Example Index