Swift beginners-advanced syntax and swift beginners

Source: Internet
Author: User

Swift beginners-advanced syntax and swift beginners

Default Binding (Optional Binding is automatically set to null)

Add ?, Nil can be bound by default.

Var window: UIWindow?

That is to say, if the value of window is not assigned, the value of window is nil.

This is different from the principle of automatic nil setup in the ARC mode in Objective-C. NilType exists in Swift, and its inverse operation is Unwrapping Optionals)


Value (Unwrapping Optionals)

Available! Remove the non-null values in the window variable (which has been bound by default). Be sure to set the value of the non-null type. Otherwise, a running error is reported.



Default chain



Use Unowned References to solve circular References




Syntax problems in taylor swift lyrics

There is a commonly used method for omitting the title of a newspaper. The active method uses ing and the passive method uses the past word segmentation.
For example, stuck in traffic is a traffic jam.
This is similar, but it is more about rhyming. It is very common to omit the lyrics. Chinese lyrics are not very syntactic.
Complete should be I have been ....
Or the Passive Meaning of "I am stuck here but you cannot see it"
However, regular articles cannot be used.
This is my idea for reference.
Haha ..........

Syntax in the lyrics of taylor swift's red album

Generally, the lyrics do not focus on syntaxes, or even some syntaxes are incorrect. Therefore, it is not good to listen to English songs and learn grammar.
 

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.