如何在 Swift 中使用 for 循环遍历元组数组

Question

I have an array of tuples defined as:

var points2D:Array=[(1,1),(2,3),(4,3),(9,5),(3,3),(7,6),(5,6)]

when trying to go through it like this:

func foo(){
    for (x,y) in points2D{
    }
}

I get this error message:

'τ_0_0' is not convertible to '(@lvalue Array, @lvalue Array)'

What does it mean, and what am I doing wrong?

Answer 1

The type of points2D is not Array , but rather Array<(Int,Int)> , so let Swift infer the type:

 var points2D = [(1,1),(2,3),(4,3),(9,5),(3,3),(7,6),(5,6)]

or set the correct type explicitly:

var points2D:Array<(Int,Int)> = [(1,1),(2,3),(4,3),(9,5),(3,3),(7,6),(5,6)]