Swift 面试题与答案
问题 36. Explain the 'escaping' closure and why it's necessary in Swift.
An 'escaping' closure is a closure that is called after the function it was passed to has returned. It's necessary when the closure is stored or outlives the scope of the function.
问题 37. What is the purpose of the 'self' keyword in Swift?
'self' is used to refer to the instance of the current type, and it's often required to distinguish between instance variables and parameters with the same name.
问题 38. Explain the difference between 'defer' and 'finally' in Swift.
'defer' is used to execute a block of code just before the scope is exited, while 'finally' is not used in Swift. Instead, error handling with 'defer' and 'catch' is more idiomatic.
问题 39. What is the 'lazy' keyword used for in Swift?
'lazy' is used to delay the initialization of a property until it's accessed for the first time.
问题 40. Explain the purpose of 'inout' parameters in Swift functions.
'inout' parameters allow a function to modify the value of the parameter directly, and any changes made inside the function affect the original value outside the function.
用户评价最有帮助的内容:
- What is Swift?
- Explain optionals in Swift.
- What is the difference between 'let' and 'var' in Swift?
- What are property observers in Swift?
- What is the purpose of the 'static' keyword in Swift?