C + + Atol

Function name: Atol functions: Convert string to grow integer usage: Long atol (const char *nptr);Introduction Edit Related functions: Atof,atoi,strtod,strtol,strtoul header file: #include <stdlib.h> define function: Long atol (const char *nptr); function Description: Atol () The parameter nptr string is scanned, skipping the previous empty characters (meaning that the left space of the string is ignored), until a number or sign is encountered to start the conversion, and then the non-numeric or string ends (' \ ") ends the conversion and returns the result. Return value: Returns the number of long integers after the conversion. If the passed-in string is empty, or if the string contains a non-Arabic sequence, the function returns the default value of 0. Additional instructions: ATOL () with the use of Strtol (nptr, (char**) null,10);2 Procedure Example 1 #include <stdlib.h> #include <stdio.h> int main( void ) {      long l;      char *str =  "98765432" ;      l =  atol (str);  /* 原来为l = atol(str); */      printf ( "string = %s integer = %ld\n" , str, l);      return (0); }3 Procedure Example 2

/* Convert string A and string B to numbers and add */

#include<stdlib.h> main() {      char a[]=”1000000000”;      char b[]=” 234567890”;      long c;      c= atol (a)+ atol (b);      printf (“c=%d\n”,c); }Perform c=1234567890------------------------------------------------------------------------------------------------ -----------_variant_t vt_decimal ext. int

_variant_t Vtsumcount = _bstr_t ("0");
Vtsumcount.changetype (Vt_decimal);

Char csumvalue[16]={0};
strcpy (Csumvalue, (LPCSTR) _bstr_t (Vtsumcount));

int sumcount;

Sumcount = Atoi (Csumvalue);

C + + Atol