Validate against empty UITextField?

Question

What is the value of a UITextField when it is empty? I can't seem to get this right.

I've tried (where `phraseBox' it the name of the said UITextField

if(phraseBox.text != @""){

and

if(phraseBox.text != nil){

What am I missing?

score 21 · Accepted Answer · edited Jan 30 '11 at 18:55

21

// Check to see if it's blank
if([phraseBox.text isEqualToString:@""]) {
  // There's no text in the box.
}

// Check to see if it's NOT blank
if(![phraseBox.text isEqualToString:@""]) {
  // There's text in the box.
}

edited Jan 30 '11 at 18:55

Mike Wheaton

492
4
15

answered Jun 08 '10 at 23:22

Raphael Caixeta

7,808
9
51
76

Gotta wait 15 minutes to accept according to SO rules. I have 13 more min to test this, hehe ... – Moshe Jun 08 '10 at 23:24
Keep always simple :) – fyasar Feb 03 '14 at 12:58
What if the user just enters a bunch of spaces? – Supertecnoboff Aug 22 '15 at 20:29

score 13 · Answer 2 · edited Apr 14 '15 at 13:56

found this at apple discussions when searching for the same thing,thought ill post it here too. check the length of the string :

NSString *value = textField.text;
if([value length] == 0) {

}

or optionally trim whitespaces from it before validation,so user cannot enter spaces instead.works well for usernames.

NSString *value = [textField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

if([value length] == 0) {
// Alert the user they forgot something
}

score 1 · Answer 3 · edited Feb 05 '14 at 10:35

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{

  NSString *fullText = [textField.text stringByAppendingString:string];      
  if ((range.location == 0) && [self isABackSpace:string]) {
    //the textFiled will be empty
  }
  return YES;
}

-(BOOL)isABackSpace:(NSString*)string {
  NSString* check =@"Check";
  check = [check stringByAppendingString:string];
  if ([check isEqualToString:@"Check"]) {
    return YES;
  }
  return NO;
}

score 1 · Answer 4 · edited Apr 13 '12 at 13:26

1

Try following code

textField.text is a string value so we are checking it like this

if([txtPhraseBox.text isEqualToString:@""])

{

// There's no text in the box.

}

else

{

NSLog(@"Text Field Text == : %@ ",txtPhraseBox.text);

}

edited Apr 13 '12 at 13:26

Akshay Aher

2,525
2
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answered Mar 29 '12 at 12:16

Rohit Wankhede

506
5
15

mmackh · Answer 5 · 2013-01-12T20:35:56.207

0

Actually, I ran into slight problems using Raphael's approach with multiple text fields. Here's what I came up with:

if ((usernameTextField.text.length > 0) && (passwordTextField.text.length > 0)) {
    loginButton.enabled = YES;
} else {
    loginButton.enabled = NO;
}

edited Jan 12 '13 at 20:35

answered Jul 23 '12 at 09:18

mmackh

3,550
3
35
51

Hemant Dixit · Answer 6 · 2012-08-06T10:23:37.413

0

Use for text field validation:

-(BOOL)validation{
 if ([emailtextfield.text length] <= 0) {
  [UIAlertView showAlertViewWithTitle:AlertTitle message:AlertWhenemailblank];
  return NO; }  
 return YES;}

edited Aug 06 '12 at 10:23

answered Jul 23 '12 at 11:22

Hemant Dixit

1,145
8
12

score 0 · Answer 7 · answered Apr 23 '15 at 13:05

Validation against empty UITextfield. if you don't want that UITextField should not accept blank white spaces. Use this code snippet:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    NSString *resultingString = [textField.text stringByReplacingCharactersInRange: range withString: string];
    NSCharacterSet *whitespaceSet = [NSCharacterSet whitespaceCharacterSet];
    if  ([resultingString rangeOfCharacterFromSet:whitespaceSet].location == NSNotFound)      {
        return YES;
    }  else  {
        return NO;
    }
}

Validate against empty UITextField?

7 Answers7