如何在Swift中将数组中的每个Int值乘以一个常数?
问题描述：
说，我有一个数组[20, 2, 3]
如何在Swift中将此数组的每个Int值相乘?
那么2个数组变成[40, 4, 6]，3个数组变成[60, 6, 9]，依此类推?
Say, I have an array [20, 2, 3]
How can I multiply each Int value of this array in Swift?
So 2 x array becomes [40, 4, 6], 3 x array becomes [60, 6, 9] and so on?
答
您可以使用.map():
let values = [20, 2, 3]
let doubles = values.map { $0 * 2 }
let triples = values.map { $0 * 3 }
如果要就地进行更新:
var values = [20, 2, 3]
values.enumerated().forEach { index, value in
values[index] = value * 2
}
// values is now [40, 4, 6]