Swift-Initial (3)

Loop OC-style for

Swift-style for

• Periodic summary
  • SwiftUse in keywords to indicate the range of loops
  • 0..<10Represents from 0 to 9
  • 0...10Represents from 0 to 10
  • Note that spaces do not appear between

Special wording

• Periodic summary
  • If you don't care about the index of the loop itself, you can use the _ ignore
  • This technique has been seen in previous branch walkthroughs

String

In the vast majority of cases in Swift, it is recommended to use the String type

Use StringThe cause

• Stringis a structural body with higher performance
  • StringCurrently has the most nsstring function
  • StringSupports direct traversal
• NSStringis an OC object with slightly poor performance
• SwiftProvides String NSString seamless transitions between and

Traversing strings

string concatenation

• Periodic summary
  • "" \(变量名) quickly stitch strings in a way that is used directly in
  • My little friend and I are never going to think about stringWithFormat it:D

formatting strings

• Periodic summary
  • In real-world development, if you need to specify a string format, you can use String(format:...) the way
  • Note: The following parameters need to be placed in an array

Combination of String & Range

Here's the super-laborious code.

Suggested wording

Array Simple Experience

// 像 OC 一样打印println(arr as NSArray)

Types of objects saved in an array

• Periodic summary
  • arrays are defined using [], which is the same as OC
  • If all content types are consistent during initialization, the content of that type is saved in the optional array
  • If all content types are inconsistent during initialization, the selected array holds theNSObject

Common Array Operations

• Periodic summary
  • If you specify the type of the Save object when you define the array, you cannot add other types of content to the array
  • can use[String]()
  • letThe defined array is不可变的
  • varThe defined array is可变的

Dictionary

function Simple Walkthrough

• Periodic summary
  • function definition Format:func 函数名(参数: 参数类型...) -> 返回值 { // 代码实现 }
  • If there is no return value, -> 返回值 you can omit the
  • ->It's a very interesting symbol.
  • By default, when a function is called, the first parameter name is omitted

Special handling of parameter names requires parameter names

Omit parameter name

Circular references for closures

Lazy Loading

• Format:

• Lazy loading is essentially a definition and execution of a closure

Getter & Setter Custom Person class

Getter & Setter

　　

• SwiftGetter & Setter in the above form is seldom used

Didset

• In OC, we usually want to do some extra work after assigning a value to a variable.
• The most classic application is to complete the cell's fill with the model's setup method when customizing the cell.

Computed properties

• getterproperties that implement only methods are called computed properties, equivalent to properties in OC ReadOnly
• Computed properties themselves do not occupy memory space
• You cannot set a value for a computed property
• Computed properties can use the following code shorthand

constructor function

Destructors

 

Swift-Initial (3)