int isNumber(char s[])
{
for (int i = 0; s[i]!= '\0'; i++)
{
if (isdigit(s[i]) == 0)
return 0;
}
return 1;
}
#include <stdio.h>
#include <stdlib.h>
int main()
{
char ch[]="123";
int a=atoi(ch);
printf("%d",a);
return 0;
}#include<string>
string str1 = "45";
string str2 = "3.14159";
string str3 = "31337 geek";
int myint1 = stoi(str1);
std::cout<<stoi(str1);const char *number = "10";
char *end;
long int value = strtol(number, &end, 10);
if (end == number || *end != '\0' || errno == ERANGE)
printf("Not a number");
else
printf("Value: %ld", value);