Range in a for loop

[inleemind]

I am trying to read a string and tell whether or not it is a number or not. The program below work but i believe my problem is in my range. the loop is only reading 3 digits in a number. how do i make it read all the characters up into a space ?

#include <iostream> // libraries
#include <iomanip>
#include <string>

using namespace std;

int main()
{
char str[80];
int i;
int counter=0;
cout << "enter a string "; // prompting user
cin.getline(str,80); // geting line
cout<<endl;
i =0;
while (str[i]!='\0')
{
if(str[i] == ' ')
{
for(int x=i-3; x<i; ++x)
{
if (str[x]<'0' || str[x] >'9')
{
++counter;
}
}
if(counter>=1)
{
for(int x=i-3; x<i; ++x)
{
cout<<str[x];
}
cout<<" is not a number" << endl;
}

else
{
for(int x=i-3; x<i; ++x)
{
cout<<str[x];
}
cout<<" is a number" << endl;
}
counter=0;
}
i++;
}
}

enter a string 435 dsaf 23 sd 3

435 is a number
saf is not a number
 23 is not a number
 sd is not a number
Press any key to continue . . .

[oN3AqMoL]

If you want to know a string's length, use the string.length object.

[codekiddy]

isdigit()
http://www.cplusplus.com/reference/clibrary/cctype/isdigit/
and
peek()
http://www.cplusplus.com/reference/iostream/istream/peek/