What is the Swift equivalent of isEqualToString in Objective-C?

I am trying to run the code below:

import UIKit

class LoginViewController: UIViewController {

@IBOutlet var username : UITextField = UITextField()
@IBOutlet var password : UITextField = UITextField()

@IBAction func loginButton(sender : AnyObject) {

    if username .isEqual("") || password.isEqual(""))
    {
        println("Sign in failed. Empty character")
    }
}

My previous code was in Objective-C, which was working fine:

 if([[self.username text] isEqualToString: @""] ||
    [[self.password text] isEqualToString: @""] ) {

I assume I cannot use isEqualToString in Swift. Any help would be appreciated.

Solution 1:

With Swift you don't need anymore to check the equality with isEqualToString

You can now use ==

Example:

let x = "hello"
let y = "hello"
let isEqual = (x == y)

now isEqual is true.

Solution 2:

Use == operator instead of isEqual

Comparing Strings

Swift provides three ways to compare String values: string equality, prefix equality, and suffix equality.

String Equality

Two String values are considered equal if they contain exactly the same characters in the same order:

let quotation = "We're a lot alike, you and I."
let sameQuotation = "We're a lot alike, you and I."
if quotation == sameQuotation {
    println("These two strings are considered equal")
}
// prints "These two strings are considered equal"
.
.
.

For more read official documentation of Swift (search Comparing Strings).

Solution 3:

I addition to @JJSaccolo answer, you can create custom equals method as new String extension like:

extension String {
     func isEqualToString(find: String) -> Bool {
        return String(format: self) == find
    }
}

And usage:

let a = "abc"
let b = "abc"

if a.isEqualToString(b) {
     println("Equals")
}

For sure original operator == might be better (works like in Javascript) but for me isEqual method gives some code clearness that we compare Strings

Hope it will help to someone,

Solution 4:

In Swift, the == operator is equivalent to Objective C's isEqual: method (it calls the isEqual method instead of just comparing pointers, and there's a new === method for testing that the pointers are the same), so you can just write this as:

if username == "" || password == ""
{
    println("Sign in failed. Empty character")
}