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iOS

Posted by Trevor Wood
Trevor Wood
17,828 Points

A little confused on how exactly this snipet of code works

So, a little confused here.

What's the 0 for? Where did total and score come from? are they variables? Also, why is in there?

let scores = [10,12,11,10,12,9]
let totalScore = scores.reduce(0, combine: {total, score in total + score })

1 Answer

Moritz Lang
Moritz Lang
25,909 Points

Reduce is a higher order function that have the same result as the following:

let scores = [10,12,11,10,12,9]
var totalScore = 0
for score in scores {
    totalScore += score
}

With reduce you can write it like you did above. 0 represents totalScore's initial value. Combine is a function that combines two values. You named these values total and score, so you use those values to access totalScore and score in the function. Last but not least you add score to total and have the total score as result.

Trevor Wood
Trevor Wood
17,828 Points

Ahhh I see, Thank you so much!