arrays - 如何完全遍历数组？

Question

我有以下代码，我试图根据 ChaptersToRead 打印出 booksAssigned 和 booksAssignedDue

var books:[String] = ["Hobbit","LOTR","Fellowship"]
var chaptersToRead:[[Int]] = [[1],[1,2],[2]]

var booksAssigned:[String] = []
var booksAssignedDue:[String] = []

for (index, chapters) in chaptersToRead.enumerated() {
    if chapters.contains(1) {
        booksAssigned.append(books[index])
    }
    else
    {
        booksAssignedDue.append(books[index])
    }
}

我期望的输出是这样的

print(booksAssigned) = ["Hobbit","LOTR"]
print(booksAssignedDue) = ["LOTR","Fellowship"]

但是我明白了

print(booksAssigned) = ["Hobbit","LOTR"]
print(booksAssignedDue) = ["Fellowship"]

我做错了什么？

Answer 1

试试这个:

for (index, chapters) in chaptersToRead.enumerated() {
    if chapters.contains(1) {
        booksAssigned.append(books[index])
    }
    //You should not use `else` here.
    if chapters.contains(2) {
        booksAssignedDue.append(books[index])
    }
}

如果在marked处使用else，则添加到booksAssigned的书不能添加到booksAssignedDue。