57 lines
841 B
Swift
57 lines
841 B
Swift
import Foundation
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// let变量不可变
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let myName = "Gary"
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let yourName = "Foo"
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// var变量可以改变
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// structur
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var names = [
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myName,
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yourName
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]
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names.append("Mike")
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// 值拷贝
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let foo = "Foo"
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var foo2 = foo
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foo2 = "Foo2"
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foo
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let moreName = [
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"Gary",
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"Mike",
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"Sara"
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]
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// let -> var
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var copy = moreName
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copy.append("Foo")
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moreName
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// class 指针传递，let只保证指针不改变
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let oldArray = NSMutableArray(
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array: ["Mike", "Paul"]
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)
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oldArray.add("Baz")
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var newArray = oldArray
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newArray.add("Qux")
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newArray
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oldArray
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// 一些函数签名表示不改变变量，实际上改变
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let someNames = NSMutableArray(
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array: ["Mike", "Paul"]
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)
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func changTheArray(_ array: NSArray) {
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let copy_address = array as! NSMutableArray
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copy_address.add("Bazz")
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}
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changTheArray(someNames)
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someNames
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