Check out example codes for "let values = [3.0,6.0,9.0,1.0] let squares = values.map {$0 * $0} print(squares)". It will help you in understanding the concepts better.
Code Example 1
let values = [3.0,6.0,9.0,1.0]
let squares = values.map {$0 * $0}
print(squares)
Code Example 2
func sumSq(s: [Int]) -> Int { return s.map{$0 * $0}.reduce(0, +)}
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