Read space separated numbers from char array to separate int(s) - c++

Question

I have a char array (lets' say "13 314 43 12") and i want to put the first number (13) into a separate integer . how do i do that ? is there any way like splitting the first number into 10 + 3 and then adding them to the int ?

Answer 1

I am not sure what you mean by getting 1 and 3, but if you want to split the space-separated string into integers I suggest using a stream.
std::istringstream iss(s);
int n;
while(iss >> n)
{
std::cout << "Integer: " << n << std::endl;
}
[edit] Alternatively, you could parse the string yourself, something like this:
char* input = "13 314 43 12";
char* c = input;
int n = 0;
for( char* c = input; *c != 0; ++c )
{
if( *c == ' ')
{
std::cout << "Integer: " << n << std::endl;
n = 0;
continue;
}
n *= 10;
n += c[0] - '0';
}
std::cout << "Integer: " << n << std::endl;

Answer 2

#include <cstring>
#include <iostream>
#include <stdlib.h>
int main ()
{
char str[] = "13 45 46 96";
char * pch = strtok (str," ");
while (pch != NULL)
{
std::cout << atoi(pch) << "\n"; // or int smth=atoi(pch)
pch = strtok (NULL, " ");
}
return 0;
}

Answer 3

If you just want the first number, just use a function like atoi() or strtol(). They extract a number until it runs into the null terminated character or a non-numeric number.

Answer 4

According to your question I think following code will give some idea.
#include <string>
#include <iostream>
using namespace std;
int main(){
char s[] = "13 314 43 12";
//print first interger
int v = atoi(s);
cout << v << std::endl;
//print all integer
for (char c : s){
if (c == ' ' || c == '\0'){
}else{
int i = c - '0';
cout << i << std::endl; // here 13 print as 1 and 3
}
}
}
If you want to print first number you can use
int v = atoi(s);
cout << v << std::endl;
If you want to split and print all integers Ex: 13 as 1,3
for (char c : s){
if (c == ' ' || c == '\0'){
}else{
int i = c - '0';
cout << i << std::endl; // here 13 print as 1 and 3
}
}