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How to check for an undefined or null variable in Swift?


"All I want to do is execute the if-statement if 'goBack' is undefined. How can I do that?"

To check whether a variable equals nil you can use a pretty cool feature of Swift called an if-let statement:

if let goBackConst = goBack {
    firstName.text = passFirstName1
    lastName.text = passLastName1
}

It's essentially the logical equivalent of "Can we store goBack as a non-optional constant, i.e. can we "let" a constant = goBack? If so, perform the following action."


Categories : IOS

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