在开发过程中，遇到的多种相似的逻辑判断，会造成臃肿的 if else 代码结构不够清晰

利用对象来实现 if else 的逻辑判断

将判断条件作为对象的属性名，将处理逻辑作为属性值，通过对象属性查找的方式来进行逻辑判断，这种写法特别适合一元条件判断的情况。

const actions = {
  '1': ['processing','IndexPage'],
  '2': ['fail','FailPage'],
  '3': ['success','SuccessPage'],
  '4': ['cancel','CancelPage'],
  'default': ['other','Index'],
}

const onButtonClick = (status)=>{
  let action = actions[status] || actions['default'],
      logName = action[0],
      pageName = action[1]
  doSomething(logName)
  Jump(pageName)
}

使用ES6的map，好处：

1. Map可以用任何类型的数据作为key
2. 可以通过size属性很容易地得到一个Map的键值对个数，而对象的键值对个数只能手动确认

const actions = new Map([
  [1, ['processing','IndexPage']],
  [2, ['fail','FailPage']],
  [3, ['fail','FailPage']],
  [4, ['success','SuccessPage']],
  [5, ['cancel','CancelPage']],
  ['default', ['other','Index']]
])

const onButtonClick = (status)=>{
  let action = actions.get(status) || actions.get('default')
  sendLog(action[0])
  jumpTo(action[1])
}

多个判断条件的情况

把两个条件拼接成字符串，并通过以条件拼接字符串作为键，以处理函数作为值的Map对象进行查找并执行

const actions = new Map([
  ['guest_1', ()=>{/*do sth*/}],
  ['guest_2', ()=>{/*do sth*/}],
  ['guest_3', ()=>{/*do sth*/}],
  ['master_1', ()=>{/*do sth*/}],
  ['master_2', ()=>{/*do sth*/}],
  ['master_3', ()=>{/*do sth*/}],
  ['default', ()=>{/*do sth*/}],
])

const onButtonClick = (identity,status)=>{
  let action = actions.get(`${identity}_${status}`) || actions.get('default')
  action.call(this)
}

或者使用对象的作为key

const actions = new Map([
  [{identity:'guest',status:1},()=>{/*do sth*/}],
  [{identity:'guest',status:2},()=>{/*do sth*/}],
  [{identity:'master',status:1},()=>{/*do sth*/}],
  [{identity:'master',status:2},()=>{/*do sth*/}],
])

const onButtonClick = (identity,status)=>{
  let action = [...actions].filter(([key,value])=>(key.identity == identity && key.status == status))
  action.forEach(([key,value])=>value.call(this))
}