- (BOOL)isPureInt:(NSString *)string{
NSScanner* scan = [NSScanner scannerWithString:string]; 
int val; 
return [scan scanInt:&val] && [scan isAtEnd];
}

- (BOOL)isPureFloat:(NSString *)string{
NSScanner* scan = [NSScanner scannerWithString:string]; 
float val; 
return [scan scanFloat:&val] && [scan isAtEnd];
}

- (BOOL)isPureNumandCharacters:(NSString *)text 
{ 
  for(int i = 0; i < [text length]; ++i) {
    int a = [text characterAtIndex:i]; 
    if ([self isNum:a]){
      continue; 
    } else { 
      return NO; 
    } 
  } 
  return YES; 
}

- (BOOL)isAllNum:(NSString *)string{
  unichar c;
  for (int i=0; i<string.length; i++) {
    c=[string characterAtIndex:i];
    if (!isdigit(c)) {
      return NO;
    }
  }
  return YES;
}

- (BOOL)isPureNumandCharacters:(NSString *)string 
{ 
string = [string stringByTrimmingCharactersInSet;[NSCharacterSet decimalDigitCharacterSet]];
if(string.length > 0) 
{
   return NO;
} 
return YES;
}