Question

在这一天上花了一整天。我有一系列费用填充我的tableview。用户可以从tableview中选择一行来编辑费用，其中包括姓名，金额，截止日期等。

我不希望用户能够输入重复的名称。我的意思是，我想检查他们对数组的输入，以确保名称不存在。这对我来说听起来很简单，但由于某种原因，我无法让它发挥作用。

这是我尝试过的：

代码＃1：

    var duplicateCount = 0
    for item in Expense.expensesArray.filter({ $0.ownerName == currentUserName }).filter({ $0.category == expense?.category }) {
        if item.expenseName != expense?.expenseName {
            print("no duplicates found in \(item.expenseName). moving on")
        } else if item.expenseName == expense?.expenseName {
            duplicateCount += 1
            print("duplicate found in \(item.expenseName)")
        }
    }

代码＃2：（与＃1非常相似）

    var duplicatesAmount: Int = 0
    for expense in Expense.expensesArray.filter({ return $0.ownerName == currentUserName }).filter({ $0.category == expense?.category }) {
        if expense.expenseName.lowercased() == expenseNameTextField.text?.lowercased() {
            duplicatesAmount += 1
            print("POTENTIAL DUPLICATE #\(duplicatesAmount): ",expense.expenseName)
        }
    }
    // if there is more than one expense in the array with the same name, return true
    if duplicatesAmount > 1 {
        return true
    } else {
        return false
    }

编辑：代码运行是否有重复。它永远不会看到重复，即使我故意把它放进去。

更新：这有效。

if expense?.expenseName == expenseNameTextField.text {
        updateExpenseInfo()
    } else {
        // iterate over the array and see if new name is found anywhere
        let dupArray = Expense.expensesArray.filter({ $0.ownerName == currentUserName && $0.category == expense?.category && $0.expenseName == expenseNameTextField.text })
        if dupArray.isEmpty {
            updateExpenseInfo()
        } else {
            duplicateNameAlert()
        }
    }

Answer 1

你可以这样做：

struct Object {
    let name: String
    let amount: Int

    init(name: String = "", amount: Int = 0) {
        self.name = name
        self.amount = amount
    }
}

let a = Object(name: "Foo", amount: 10)
let b = Object(name: "Bar", amount: 20)

let array = [a, b]

func contains(value: String) -> Bool {
    return array.filter({ $0.name == value }).isEmpty
}

print(contains(value: "Foo")) // true
print(contains(value: "Test")) // false

所以你基本上只需添加contains函数并返回array.filter({ $0.name == value }).isEmpty。如果它返回true则保存否则不保存。您传递输入值的值。

如何确保用户无法输入重复项？

1 个答案: