Compound assignment operators

Swift has shorthand operators that combine one operator with an assignment, so you can change a variable in place. These look like the existing operators you know – +, -, *, and /, but they have an = on the end because they assign the result back to whatever variable you were using.

For example, if someone scored 95 in an exam but needs to be penalized 5 points, you could write this:

var score = 95
score -= 5

Similarly, you can add one string to another using +=:

var quote = "The rain in Spain falls mainly on the "
quote += "Spaniards"

SPONSORED In-app subscriptions are a pain to implement, hard to test, and full of edge cases. RevenueCat makes it straightforward and reliable so you can get back to building your app. Oh, and it's free if your app makes less than $10k/mo.

Learn more

Sponsor Hacking with Swift and reach the world's largest Swift community!