Check if an NSString is a double [duplicate] - ios

Question

This question already has an answer here:
parsing NSString to Double
(1 answer)
Closed 7 years ago.
How do I check if a UITextField's text is a double or not?
Simple validation required, if the entered textfield value is a valid double value or not?
Valid double values: 1.00, 1.01 or 1.00001
Invalid double values: .0.1, .001.11, 1.0.1 or 1...0 etc.
mytxtfield.text=#"12.00"; //ok
mytxtfield.text=#"1.2..0"; // is invalid and so on
EDIT: My answer that works thanx sahzad ali
//------------
-(BOOL)isvalidDouble:(NSString*)txtstring
{
NSArray *dotSeparratedArray = [txtstring componentsSeparatedByString:#"."];
NSInteger count=[dotSeparratedArray count];
count=count-1;
if(count >1)
{
return TRUE ; //invalid
}
return FALSE; //valid
}

Answer 1

You can limit user from entering multiple dots or you can use same logic in your TextFieldDidEndEditing method. If componentsSeparatedByString returns greater than 2 it means there are multiple dots.
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSString *myString = [textField.text stringByReplacingCharactersInRange:range withString:string];
NSArray *dotSeparratedArray = [myString componentsSeparatedByString:#"."];
if([dotSeparratedArray count] >= 2)
{
NSString *string1=[NSString stringWithFormat:#"%#",[dotSeparratedArray objectAtIndex:1]];
return !([string1 length]>1);
}
return YES;
}

Answer 2

I don't know whether or not this will serve your purposes, but you could use NSNumberFormatter and customize it to your needs:
NSNumberFormatter *myFormatter = [[NSNumberFormatter alloc] init];
[myFormatter setFormatWidth:7];
[myFormatter setPaddingCharacter:#"0"];
[myFormatter setMinimumSignificantDigits:0];
[myFormatter setMinimum:#0];
[myFormatter setMaximum:#9999999];
[myClientIDTextField setFormatter:myFormatter];