打字稿中开关的替代品答案

【问题标题】：alternative of switch in typescript打字稿中开关的替代品
【发布时间】：2021-09-13 05:43:00
【问题描述】：

我正在尝试为我的开关柜考虑任何替代方案，因为它很长我有嵌套的开关盒，看起来像这样

switch (currentTab) {
            case pending:
                switch (status) {
                    case approved:
                    case denied:
                        break;

                    case partialApproved:
                        finalUpdatedInvoiceAmount = updatedInvoiceAmount - (feeAmount - (approvedFeeAmount || 0));
                        break;
                }
                break;

            case approved:
                switch (status) {
                    case denied:
                    case partialApproved:
                        finalUpdatedInvoiceAmount = updatedInvoiceAmount - (feeAmount - (approvedFeeAmount || 0));
                        break;
                }
                break;

            case denied:
                switch (status) {
                    case approved:
                    case partialApproved:
                        finalUpdatedInvoiceAmount = oldApprovedFeeAmount ? updatedInvoiceAmount + (feeAmount - oldApprovedFeeAmount) : updatedInvoiceAmount - (feeAmount - (approvedFeeAmount || 0));
                        break;
                }
                break;

            case partiallyApprovedTab:
                switch (status) {
                    case approved:
                    case denied:
                    case partialApproved:
                        finalUpdatedInvoiceAmount = oldApprovedFeeAmount ? updatedInvoiceAmount + (feeAmount - oldApprovedFeeAmount) : updatedInvoiceAmount - (feeAmount - (approvedFeeAmount || 0));
                        break;
                }
                break;
        }

这是另一种可能性吗？由于代码非常庞大，以后可能会进入其他情况。

【问题讨论】：

if (currentTab == pending && status == partialApproved) ... else if (currentTab == approved && [denied, partialApproved].includes(status)) ...…?
我也遇到了类似的问题，但我必须学习很多不同的方法来避免长时间运行的 switch case。通过链接，它可能会帮助你[替代切换案例](ultimatecourses.com/blog/…)

标签： javascript angular typescript switch-statement object-literal

【解决方案1】：

也许你可以试试 handlerMap：

const handler1 = () => { finalUpdatedInvoiceAmount = updatedInvoiceAmount - (feeAmount - (approvedFeeAmount || 0)); }
const handler2 = () => { finalUpdatedInvoiceAmount = oldApprovedFeeAmount ? updatedInvoiceAmount + (feeAmount - oldApprovedFeeAmount) : updatedInvoiceAmount - (feeAmount - (approvedFeeAmount || 0)); }

const handlerMap = {
  [pending]: {
    [partialApproved]: handler1
  },
  [approved]: {
    [denied]: handler1,
    [partialApproved]: handler1,
  },
  [denied]: {
    [approved]: handler2,
    [partialApproved]: handler2,
  },
  [partiallyApprovedTab]: {
    [approved]: handler2,
    [denied]: handler2,
    [partialApproved]: handler2,
  }
}

handlerMap[currentTab] && handlerMap[currentTab][status] && handlerMap[currentTab][status]()
// handlerMap[currentTab]?.[status]?.()

【讨论】：