Check if NSString is numeric(integer or float)

How to check if NSString is numeric (integer or float):

NSScanner *scan = [NSScanner scannerWithString:@"string"];

if (![scan scanFloat:NULL] || ![scan isAtEnd])

{

   NSlog (@"string exist like 'abbc','12ww','1.5w',' 5 ' etc");

}

else

{

       NSlog (@"only numeric value like '12','12.5','1.5' etc");

}