Thread: is_int question

hi..
i was wondering if anyone knew a c++ substitute for the php function is_int: http://www.php.net/is_int

please reply if you do (and also with which headers i need to include)

thanks!
laney :/

A variable is an int if you declare it as type int...

isdigit() is the closest standard function, in <cctype> or <ctype.h>.

ok maybe you need to see my code then..

i declare the variable like this:

int range;

and then i get input from a cin:

cout<<"Enter number range (1-?): ";
cin>>range;

(this is in a loop.. the loop is here (to stop a user entering 0))

do
{
cout<<"Range must be greater than 0.\r\n";
cout<<"Enter number range (1-?): ";
cin>>range;
} while (range <= 0);

the problem is if a user enters something that isn't a number then it goes into an infinite loop of the two couts above... i guessed something like is_int would fix it but i can't seem to find anything :/

Try something like -

int i;
cin >> i;
while(cin.fail())
{
cin.clear();
cin.ignore(1);
cin >> i;
}

ohh works thanks

Code:

do
{
	cout<<"Range must be greater than 0.\r\n";
	cout<<"Enter number range (1-?): ";
	cin>>range;
	while(cin.fail()) 
	{ 
		cin.clear(); 
		cin.ignore(1); 
		range = 0;
	}
} while (range <= 0);