Reputation: 219
So, I'm developing an app signUp screen. I'm trying to check each field on the signUp screen to see if it's empty, and if it is, display an error message in a label to the user. I've been using a chain of else-ifs
if ((self.firstNameField.text?.isEmpty) != nil) {
errorLabel.text = "first name missing"
errorLabel.hidden = false
}
else if ((self.lastNameField.text?.isEmpty) != nil) {
errorLabel.text = "last name missing"
errorLabel.hidden = false
}
else if ((self.emailField.text?.isEmpty) != nil) {
errorLabel.text = "email missing"
errorLabel.hidden = false
}
else if ((self.passwordField.text?.isEmpty) != nil) {
errorLabel.text = "password missing"
errorLabel.hidden = false
}
else if ((self.confirmPasswordField.text?.isEmpty) != nil) {
errorLabel.text = "password confirmation missing"
errorLabel.hidden = false
}
else if (self.passwordField.text != self.confirmPasswordField.text) {
errorLabel.text = "Passwords don't match, try again!"
errorLabel.hidden = false
}
//omitted what happens if there are no fields missing
Now, when I run the application with all the textfields empty, the errorLabel displays the message "first name missing". Putting in a first name and pressing the signup button does nothing. I want it to change to "last name missing", but it stays at "first name missing".
Upvotes: 5
Views: 5596
Reputation: 1034
You can avoid if-else cases and achieve it with one line code with ternary conditional operators in swift.
firstNameField.text?.isEmpty == true ? showError(message: ""first name missing"") : isValid()
...
}
func showError(message : String){
errorLabel.text = message
errorLabel.hidden = false
}
func isValid(){
// hide label or anything else you want
}
Upvotes: 1
Reputation: 364
if self.firstNameField.text! == "" {
errorLabel.text = "first name missing"
errorLabel.hidden = false
}
else if self.lastNameField.text! == "" {
errorLabel.text = "last name missing"
errorLabel.hidden = false
}
else if self.emailField.text! == "" {
errorLabel.text = "email missing"
errorLabel.hidden = false
}
else if self.passwordField.text! == "" {
errorLabel.text = "password missing"
errorLabel.hidden = false
}
else if self.confirmPasswordField.text! == "" {
errorLabel.text = "password confirmation missing"
errorLabel.hidden = false
}
else if !(self.passwordField.text! == self.confirmPasswordField.text!) {
errorLabel.text = "Passwords don't match, try again!"
errorLabel.hidden = false
}
Upvotes: 1
Reputation: 23596
The reason this is happening is because you are checking if self.field.text?.isEmpty != nil
. You should be checking for (self.field.text?.isEmpty ?? true)
Essentially, you're trying to get the text in the field, and if there is no text, then nil
is returned. By using field.text?
, you are making the next variable you access nil based on whether field.text
is nil. So, when there is no text, field.text == nil
, doing field.text?.isEmpty
will always return nil.
When there is text, field.text?.isEmpty
will not be nil, and will always be false, but nil != false
, so the statement will always return false
.
To fix this, you should check
if(self.field.text?.isEmpty ?? true)
which essentially means
if((self.field.text?.isEmpty == nil ? true : self.field.text?.isEmpty))
Basically, this will return true if field.text == nil
(which would make field.text?.isEmpty
nil, making the result true
due to the ??
operator), and will also return true if field.text != nil || field.text.isEmpty
. It will only return false if self.field.text != nil && !self.field.text.isEmpty
.
Another way to write this statement would be
if(self.field.text == nil || self.field.text!.isEmpty)
Upvotes: 10
Reputation: 38152
Try this out:
if self.firstNameField.text?.isEmpty {
errorLabel.text = "first name missing"
errorLabel.hidden = false
}
else if self.lastNameField.text?.isEmpty {
errorLabel.text = "last name missing"
errorLabel.hidden = false
}
else if self.emailField.text?.isEmpty {
errorLabel.text = "email missing"
errorLabel.hidden = false
}
else if self.passwordField.text?.isEmpty {
errorLabel.text = "password missing"
errorLabel.hidden = false
}
else if self.confirmPasswordField.text?.isEmpty {
errorLabel.text = "password confirmation missing"
errorLabel.hidden = false
}
else if (self.passwordField.text != self.confirmPasswordField.text) {
errorLabel.text = "Passwords don't match, try again!"
errorLabel.hidden = false
}
Upvotes: 1