本文实例讲述了es6中使用map简化复杂条件判断操作。分享给大家供大家参考,具体如下:复杂逻辑判断时需要写很多if/else,代码可读性较差,可以用es6新增的Map来简化代码列举六种实例,逐步简化
/**
* 按钮点击事件
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
if (status == 1) {

sendLog('processing') jumpTo('IndexPage')
} else if (status == 2) {

sendLog('fail') jumpTo('FailPage')
} else if (status == 3) {

sendLog('fail') jumpTo('FailPage')
} else if (status == 4) {

sendLog('success') jumpTo('SuccessPage')
} else if (status == 5) {

sendLog('cancel') jumpTo('CancelPage')
} else {

sendLog('other') jumpTo('Index')
}
}


/**
* 按钮点击事件
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
if (status == 1) {

sendLog('processing') jumpTo('IndexPage')
} else if (status == 2) {

sendLog('fail') jumpTo('FailPage')
} else if (status == 3) {

sendLog('fail') jumpTo('FailPage')
} else if (status == 4) {

sendLog('success') jumpTo('SuccessPage')
} else if (status == 5) {

sendLog('cancel') jumpTo('CancelPage')
} else {

sendLog('other') jumpTo('Index')
}
}

转化成switch简化:
/**
* 按钮点击事件
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
switch (status) {

case 1:

sendLog('processing')

jumpTo('IndexPage')

break

case 2:

case 3:

sendLog('fail')

jumpTo('FailPage')

break

case 4:

sendLog('success')

jumpTo('SuccessPage')

break

case 5:

sendLog('cancel')

jumpTo('CancelPage')

break

default:

sendLog('other')

jumpTo('Index')

break
}
}


/**
* 按钮点击事件
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
switch (status) {

case 1:

sendLog('processing')

jumpTo('IndexPage')

break

case 2:

case 3:

sendLog('fail')

jumpTo('FailPage')

break

case 4:

sendLog('success')

jumpTo('SuccessPage')

break

case 5:

sendLog('cancel')

jumpTo('CancelPage')

break

default:

sendLog('other')

jumpTo('Index')

break
}
}

将判断条件作为对象的属性名,将处理逻辑作为对象的属性值,继续简化:
const actions = {
'1': ['processing', 'IndexPage'],
'2': ['fail', 'FailPage'],
'3': ['fail', 'FailPage'],
'4': ['success', 'SuccessPage'],
'5': ['cancel', 'CancelPage'],
'default': ['other', 'Index'],
}
/**
* 按钮点击事件
* @param {number} status 活动状态:1开团进行中 2开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
let action = actions[status] || actions['default'],

logName = action[0],

pageName = action[1]
sendLog(logName)
jumpTo(pageName)
}


const actions = {
'1': ['processing', 'IndexPage'],
'2': ['fail', 'FailPage'],
'3': ['fail', 'FailPage'],
'4': ['success', 'SuccessPage'],
'5': ['cancel', 'CancelPage'],
'default': ['other', 'Index'],
}
/**
* 按钮点击事件
* @param {number} status 活动状态:1开团进行中 2开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
let action = actions[status] || actions['default'],

logName = action[0],

pageName = action[1]
sendLog(logName)
jumpTo(pageName)
}

转化成Map简化
const actions = new Map([
[1, ['processing', 'IndexPage']],
[2, ['fail', 'FailPage']],
[3, ['fail', 'FailPage']],
[4, ['success', 'SuccessPage']],
[5, ['cancel', 'CancelPage']],
['default', ['other', 'Index']]
])
/**
* 按钮点击事件
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
let action = actions.get(status) || actions.get('default')
sendLog(action[0])
jumpTo(action[1])
}


const actions = new Map([
[1, ['processing', 'IndexPage']],
[2, ['fail', 'FailPage']],
[3, ['fail', 'FailPage']],
[4, ['success', 'SuccessPage']],
[5, ['cancel', 'CancelPage']],
['default', ['other', 'Index']]
])
/**
* 按钮点击事件
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 商品售罄 4 开团成功 5 系统取消
*/
const onButtonClick = (status) => {
let action = actions.get(status) || actions.get('default')
sendLog(action[0])
jumpTo(action[1])
}

Map对象和Object对象的区别:Map的键可以是任意值,Map的键值对个数可通过size属性直接获接下来将问题升级:除去判断状态还要判断用户身份:传统写法:
const actions = new Map([
['guest_1', () => { /*do sth*/ }],
['guest_2', () => { /*do sth*/ }],
['guest_3', () => { /*do sth*/ }],
['guest_4', () => { /*do sth*/ }],
['guest_5', () => { /*do sth*/ }],
['master_1', () => { /*do sth*/ }],
['master_2', () => { /*do sth*/ }],
['master_3', () => { /*do sth*/ }],
['master_4', () => { /*do sth*/ }],
['master_5', () => { /*do sth*/ }],
['default', () => { /*do sth*/ }],
])
/**
* 按钮点击事件
* @param {string} identity 身份标识:guest客态 master主态
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 开团成功 4 商品售罄 5 有库存未开团
*/
const onButtonClick = (identity, status) => {
let action = actions.get(`${identity}_${status}`) || actions.get('default')
action.call(this)
}


const actions = new Map([
['guest_1', () => { /*do sth*/ }],
['guest_2', () => { /*do sth*/ }],
['guest_3', () => { /*do sth*/ }],
['guest_4', () => { /*do sth*/ }],
['guest_5', () => { /*do sth*/ }],
['master_1', () => { /*do sth*/ }],
['master_2', () => { /*do sth*/ }],
['master_3', () => { /*do sth*/ }],
['master_4', () => { /*do sth*/ }],
['master_5', () => { /*do sth*/ }],
['default', () => { /*do sth*/ }],
])
/**
* 按钮点击事件
* @param {string} identity 身份标识:guest客态 master主态
* @param {number} status 活动状态:1 开团进行中 2 开团失败 3 开团成功 4 商品售罄 5 有库存未开团
*/
const onButtonClick = (identity, status) => {
let action = actions.get(`${identity}_${status}`) || actions.get('default')
action.call(this)
}

用对象做键值简化:
const actions = new Map([
[{

identity: 'guest',

status: 1
}, () => { /*do sth*/ }],
[{

identity: 'guest',

status: 2
}, () => { /*do sth*/ }],
//...
])
const onButtonClick = (identity, status) => {
//下面代码使用了数组解构 [key,value] = cuurrentValue
let action = [...actions].filter(([key, value]) => (key.identity == identity && key.status == status))
action.forEach(([key, value]) => value.call(this))
}


const actions = new Map([
[{

identity: 'guest',

status: 1
}, () => { /*do sth*/ }],
[{

identity: 'guest',

status: 2
}, () => { /*do sth*/ }],
//...
])
const onButtonClick = (identity, status) => {
//下面代码使用了数组解构 [key,value] = cuurrentValue
let action = [...actions].filter(([key, value]) => (key.identity == identity && key.status == status))
action.forEach(([key, value]) => value.call(this))
}

正则作为key
const actions = () => {
const functionA = () => { /*do sth*/ }
const functionB = () => { /*do sth*/ }
return new Map([

[/^guest_[1-4]$/, functionA],

[/^guest_5$/, functionB],

//...
])
}
const onButtonClick = (identity, status) => {
let action = [...actions()].filter(([key, value]) => (key.test(`${identity}_${status}`)))
action.forEach(([key, value]) => value.call(this))
}


const actions = () => {
const functionA = () => { /*do sth*/ }
const functionB = () => { /*do sth*/ }
return new Map([

[/^guest_[1-4]$/, functionA],

[/^guest_5$/, functionB],

//...
])
}
const onButtonClick = (identity, status) => {
let action = [...actions()].filter(([key, value]) => (key.test(`${identity}_${status}`)))
action.forEach(([key, value]) => value.call(this))
}

感兴趣的朋友可以使用在线HTML/CSS/JavaScript代码运行工具:http://tools./code/HtmlJsRun测试上述代码运行效果。在线HTML/CSS/JavaScript代码运行工具在线HTML/CSS/JavaScript代码运行工具http://tools./code/HtmlJsRun关于JavaScript相关内容可查看本站专题:《JavaScript操作DOM技巧总结》、《JavaScript页面元素操作技巧总结》、《JavaScript事件相关操作与技巧大全》、《JavaScript查找算法技巧总结》、《JavaScript数据结构与算法技巧总结》、《JavaScript遍历算法与技巧总结》及《JavaScript错误与调试技巧总结》JavaScript操作DOM技巧总结JavaScript页面元素操作技巧总结JavaScript事件相关操作与技巧大全JavaScript查找算法技巧总结JavaScript数据结构与算法技巧总结JavaScript遍历算法与技巧总结JavaScript错误与调试技巧总结希望本文所述对大家JavaScript程序设计有所帮助。