Swift Constructor (initializer) and deinitializer (deinitializer)

To initialize instance attributes of struct, class, and other types.

Default constructor

 

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1. Struct Fahrenheit {
2. VaR temperature: doubleinit (){
3. Temperature = 32.0
4. }
5. }

 

VaR F = Fahrenheit () // call the default constructor Init (). No parameter is returned.

 

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1. Println ("the default temperature is \ (F. Temperature) deg F ahrenheit ")
2. // Prints "the default temperature is 32.0 ° Fahrenheit"

 

Custom Constructor

 

The definition class has two constructors: Init (fromfahrenheit :) and init (fromkelvin :)

 

 

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1. Struct Celsius {
2. VaR temperatureincelsius: Double = 0.0.
3. Init (fromfahrenheit Fahrenheit: Double ){
4. Temperatureincelsius = (Fahrenheit-32.0)
5. /1.8
6. }
7. Init (fromkelvin Kelvin: Double ){
8. Temperatureincelsius = Kelvin-273.15.
9. }
10. }
11. Let boilingpointofwater = Celsius (fromfahrenheit: 212.0)
12. // Boilingpointofwater. temperatureincelsius is 100.0
13. Let freezingpointofwater = Celsius (fromkelvin: 273.15)
14. // Freezingpointofwater. temperatureincelsius is 0.0

 

 

Deinitializer)

 

The Destructor is opposite to the constructor and called when the object is released. Use the keyword deinit. The syntax is as follows:

 

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1. Deinit {
2. // Perform thedeinitialization
3. }

 

 

Instance:

 

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1. Class player {
2. VaR coinsinpurse: int Init (Coins: INT ){
3. Println ("Call init ")
4. Coinsinpurse = coins
5. }
6. Func wincoins (Coins: INT ){
7. Coinsinpurse + = 10
8. }
9. Deinit {
10. Coinsinpurse = 0
11. }
12. }
13. VaR playerone: Player? = Player (Coins: 100)
14. Println ("coinsinpurse: \ (playerone !. Coinsinpurse)
15. Coins ")
16. Playerone = Nil
17. Println ("playerone has leftthe game ")

 

 

 

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