Extract property

The Extract Property refactoring lets you move expressions and local declarations to properties.

Extract a property

In the editor, select the expression or declaration you want to replace with a property.
Press ⌃ ⌥ E or select Refactor | Extract/Introduce | Property from the main or context menu.
If there are several expressions available for extracting, select the required one from the list that opens and press ⏎.
Select a name for the property from the list of suggestions that opens or type a new one.
If you want the property to be generated in a private category, select the Put to private category checkbox. Otherwise, the property will be declared in the header file.
Press ⏎.

Code examples

Before	After
@interface LoginViewController () // ... @end @implementation LoginViewController { } - (void)performLogin { // ... [self.loginModel loginWithEmail:email password:password completion:^(BOOL success) { // success will be extracted to // a property if (success) { [self showAlertLoginSuccess]; } else { [self showAlertLoginFailed]; } }]; }	@interface LoginViewController () // ... // Extracted property @property(nonatomic) BOOL loginSuccessful; @end @implementation LoginViewController { } - (void)performLogin { // ... [self.loginModel loginWithEmail:email password:password completion:^(BOOL success) { self.loginSuccessful = success; if (self.loginSuccessful) { [self showAlertLoginSuccess]; } else { [self showAlertLoginFailed]; } }]; }

Before

After

@interface LoginViewController ()
// ...
@end
@implementation LoginViewController {
}
- (void)performLogin {
     // ...

    [self.loginModel loginWithEmail:email password:password completion:^(BOOL success) {
        // success will be extracted to
        // a property
        if (success) {
            [self showAlertLoginSuccess];
        } else {
            [self showAlertLoginFailed];
        }
    }];
}
                        

@interface LoginViewController ()
// ...
// Extracted property
@property(nonatomic) BOOL loginSuccessful;
@end
@implementation LoginViewController {
}
- (void)performLogin {
     // ...

    [self.loginModel loginWithEmail:email password:password completion:^(BOOL success) {
        self.loginSuccessful = success;
        if (self.loginSuccessful) {
            [self showAlertLoginSuccess];
        } else {
            [self showAlertLoginFailed];
        }
    }];
}

                        

Last modified: 26 August 2021