Swift Programming Tutorial: Computed Properties
How to Use Getters and Setters in Swift
Swift programming language computed properties stand out as a distinct type of property. They differ from conventional properties by not directly holding a value. Instead, they provide a mechanism to access or modify a value by executing custom code. In brief, it’s a property that executes code to determine its value.
Computed properties are declared using the var keyword, similar to standard properties, but they include a getter method (for obtaining the value) and, if needed, a setter method (for altering the value).
Here’s a simple example of a computer property.
struct Rectangle {
var width: Double
var length: Double
var area: Double {
return width * length
}
}
The value of the area will be based on the product of the width and length. Let’s try using the struct and print the area.
var rectangle1 = Rectangle(width: 7.10, length: 11.9)
var rectangle2 = Rectangle(width: 12.7, length: 2.3)
print(rectangle1.area)
print(rectangle2.area)
Here’s the output:
84.49
29.209999999999997