swift - 这个快速代码有什么问题？索引一个元组

Question

var xypos: (Int, Int) = (x: 0, y: 0)

var nextxy: (Int, Int) = (one: 1, two: 2)

if x == 7 {
    nextxy.one = 0
} else if y == 63 {
    nextxy.two = 0
}

我收到一条错误消息，提示元组 nextxy 没有成员一或二。我使用了相同的语法并从一本书中复制过来。

Answer 1

这段代码是对的:

var xypos: (Int, Int) = (x: 7, y: 0)
var nextxy: (Int, Int) = (one: 1, two: 2)

if xypos.0 == 7 {
nextxy.0 = 0
} else if xypos.1 == 63 {
nextxy.1 = 0
}
print(xypos,nextxy)//xypos:7,0 nextxy:0,2

如果你想通过实例访问元组

var xypos: (x: Int,y: Int) = (2,2)
var nexttxy:(one: Int,two: Int) = (1,2)
if xypos.x == 7 {
    nexttxy.one = 1
  }else{
    nexttxy.two = 0
 }
print(xypos,nexttxy)//xypos:(2,2) nexttxy:(1,0)

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