Question

I need to validate some NSString that user inputs in some UITextField.

There are 2 kinds of validation I need.

1st, to judge whether a NSString object is a legal decimal number.

For example, @”100″, @”10.1″,@”0.11″, are all legal, but @”100.11.1″ is not.

2nd, to judge whether a NSString object is not a space-only string.

For example, @”abc”, @”ab—-c”, are all legal, but @”—–“, @””, are not.

here “-” means a space ” “.

How can I validate these 2 kinds of NSString?

Thanks a lot!

Answer 1

For the first part try this

NSNumberFormatter *formatter = [[[NSNumberFormatter alloc] init] autorelease];
[formatter setNumberStyle:NSNumberFormatterDecimalStyle];
[formatter setAllowsFloats:YES];
[formatter setDecimalSeparator:@"."];

NSNumber *number = [formatter numberFromString: inputString];

if(number == nil)
{
  //invalid input string
}

For the second part try this:

NSString *str = [inputString stringByReplacingOccurrencesOfString:@" " withString:@""];
if([str length] == 0)
{
    //invalid input string
}