Discover how to specify code that should be executed right before program flow exits the enclosing scope using defer statements. Understand order precedence when writing multiple defer statements.
- [Instructor] The defer statement…delays execution of its body of code until right before…control flow exits the scope in which it is used.…This could be used for performing cleanup actions…such as closing a file or a network connection.…I'll write a do statement, which simply allows me…to contain some functionality in its own scope.…Now, I'll write a defer statement to print Lift off.…And I'll follow that with a for-in loop…that iterates over a range of one to three…in reverse, printing each value.…
The defer statement executes right before…the enclosing scope exits, so Lift off…is printed after the printed numbers…in the for-in statement.…If more than one defer statement is used…within the same scope, they'll be executed…in reverse order.…Think of this like a stack, last on, first off.…I'll create another do statement,…and in it, first defer printing Action.…And then defer printing Camera.…
And defer printing Lights.…And finally, I'll print All quiet on set.…So this will print All quiet on set…and then in reverse order,…
Learn how to write code, understand Swift's key concepts and best practices, and strengthen your programming problem-solving skills. Instructor Scott Gardner teaches the fundamentals, so you'll be prepared to develop applications for iOS, macOS, and other platforms. Completing this course will enable you to not only write first-class code, but to think like a Swift developer.
- Creating playgrounds
- Defining variables and constants
- Working with characters and strings
- Working with collections and groups
- Using operators and defining custom operators
- Controlling program flow
- Defining functions and closures
- Working with classes, structures, and enumerations
- Adopting protocols
Skill Level Beginner
1. Get Started
2. Variables and Constants
3. Characters and Strings
4. Collections and Tuples
6. Control Flow
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