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iOS Object-Oriented Swift Inheritance Overriding Methods

What is +=?

class Button { var width: Double var height: Double

init(width:Double, height:Double){
    self.width = width
    self.height = height

func incrementBy(points: Double){
    width += points
    height += points


class RoundButton: Button { var cornerRadius: Double = 5.0 }

2 Answers

Maciej Sitko
Maciej Sitko
16,164 Points
property += 1

Is the shorthand notation for

property = property + 1;

In other words, incrementing itself by a number;

jason chan
jason chan
31,009 Points


shorthand is ++

basically plus 1 you'll see it a lot in for loops.

Maciej Sitko
Maciej Sitko
16,164 Points

Is it?

jason chan, Increment shorthand as you present increments value only by one and in the example, this may not be the case. We may want to increment it by arbitrary number.

Plus, to avoid confusion now I think the proper answer would be the specific one for incrementor by one:


As in this sense you'd want to explain incrementing that happens before variable assignments, not after, which on the other hand, looks like this