underscore.js學習筆記

時間 2019-11-06

標籤 underscore.js underscore 學習筆記欄目 JavaScript 简体版

原文原文鏈接

1、理清概念

一、Underscore封裝了經常使用的JavaScript對象操做方法，用於提升開發效率，Underscore還能夠被使用在Node.js運行環境。從API中，你已經能夠看出，Underscore沒有任何複雜的結構和流程，它僅僅提供了一系列經常使用的函數。若是你將API中的方法從頭到尾用一遍，你就會對它很是瞭解。

二、Underscore並無在原生的JavaScript對象原型中進行擴展，而是像jQuery同樣，將數據封裝在一個自定義對象中（下文中稱「Underscore對象」）。能夠經過調用一個Underscore對象的value()方法來獲取原生的javascript數據。javascript

三、Underscore.js是一個很精幹的庫，壓縮後只有4KB。它提供了幾十種函數式編程的方法，彌補了標準庫的不足，大大方便了JavaScript的編程。MVC框架Backbone.js就將這個庫做爲本身的工具庫。除了能夠在瀏覽器環境使用，Underscore.js還能夠用於Node.js。Underscor.js定義了一個下劃線（_）對象，函數庫的全部方法都屬於這個對象。這些方法大體上能夠分紅：集合（collection）、數組（array）、函數（function）、對象（object）和工具（utility）五大類。java

2、經常使用庫函數node

一、集合部分: 數組或對象

Javascript語言的數據集合，包括兩種結構：數組和對象。如下的方法同時適用於這兩種結構。

新建一個collection.js文件，測試underscore對集合的支持。jquery

~ vi collection.js
//加載underscore庫
var _ = require("underscore")._;

each: 對集合循環操做git

_.each([1, 2, 3], function (ele, idx) {
console.log(idx + ":" + ele);
});
=> 0:1
1:2
2:3

map: 對集合以map方式遍歷，產生一個新數組github

console.log(
_.map([1, 2, 3], function(num){
return num * 3;
})
);
=> [3, 6, 9]

reduce: 集合元素合併集的到memo算法

console.log(
_.reduce([1, 2, 3], function (memo, num) {
return memo + num;
}, 0)
);
=> 6

filter: 過濾集合中符合條件的元素。注：find:只返回第一個npm

console.log(
_.filter([1, 2, 3, 4, 5, 6], function(num){
return num % 2 == 0;
})
);
=> [ 2, 4, 6 ]

reject: 過濾集合中不符合條件的元素編程

console.log(
_.reject([1, 2, 3, 4, 5, 6], function(num){
return num % 2 == 0;
})
);
=> [ 1, 3, 5 ]

where: 遍歷list, 返回新的對象數組api

var list = [
{title:"AAA",year: 1982},
{title:"BBB",year: 1900},
{title:"CCC",year: 1982}
];
console.log(
_.where(list,{year: 1982})
);
=> [ { title: 'AAA', year: 1982 }, { title: 'CCC', year: 1982 } ]

contains:判斷元素是否在list中

console.log(
_.contains([1, 2, 3], 3)
);

invoke:經過函數名調用函數運行

console.log(
_.invoke([[5, 1, 7]], 'sort')
);
=> [ [ 1, 5, 7 ] ]

pluck: 提取一個集合裏指定的屬性值

var users = [
{name: 'moe', age: 40},
{name: 'larry', age: 50}
];
console.log(
_.pluck(users, 'name')
);
=> [ 'moe', 'larry' ]

max,min,sortBy: 取list中的最大,最小元素，自定義比較器

console.log(
_.max(users, function (stooge) {
return stooge.age;
})
);
=> { name: 'larry', age: 50 }
var numbers = [10, 5, 100, 2, 1000];
console.log(
_.min(numbers)
);
=> 2
console.log(
_.sortBy([3, 4, 2, 1 , 6], function (num) {
return Math.max(num);
})
);
=> [ 1, 2, 3, 4, 6 ]

groupBy: 把一個集合分組成多個集合

console.log(
_.groupBy(['one', 'two', 'three'], 'length')
);
=> { '3': [ 'one', 'two' ], '5': [ 'three' ] }

countBy: 把一個數據分組後計數

onsole.log(
_.countBy([1, 2, 3, 4, 5], function (num) {
return num % 2 == 0 ? 'even' : 'odd';
})
);
=> { odd: 3, even: 2 }

shuffle: 隨機打亂一個數據

console.log(
_.shuffle([1, 2, 3, 4, 5, 6])
);
=> [ 1, 5, 2, 3, 6, 4 ]

toArray: 將list轉換成一個數組

console.log(
(function () {
return _.toArray(arguments).slice(1);
})(1, 2, 3, 4)
);
=> [ 2, 3, 4 ]

size: 獲得list中元素個數

console.log(
_.size({one: 1, two: 2, three: 3})
);

二、數組部分

新建一個array.js

~ vi array.js
var _ = require("underscore")._;

first,last,initial,rest: 數組的元素操做。

var nums = [5, 4, 3, 2, 1];
console.log(_.first(nums));
console.log(_.last(nums));
console.log(_.initial(nums,1));
console.log(_.rest(nums,1));
=> 5
1
[ 5, 4, 3, 2 ]
[ 4, 3, 2, 1 ]

indexOf,lastIndexOf,sortedIndex：取索引位置

console.log(_.indexOf([4, 2, 3, 4, 2], 4));
console.log(_.lastIndexOf([4, 2, 3, 4, 2], 4));
console.log(_.sortedIndex([10, 20, 30, 40, 50], 35));
=> 0
3
3

range: 建立一個範圍整數數組

console.log(_.range(1,10));
console.log(_.range(0, -10, -1));
=> [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
[ 0, -1, -2, -3, -4, -5, -6, -7, -8, -9 ]

compact:數組去除空值

console.log(
_.compact([0, 1, false, 2, '', 3])
);
=> [ 1, 2, 3 ]

flatten:將一個嵌套多層的數組(嵌套能夠是任何層數)轉換爲只有一層的數組

console.log(
_.flatten([1, [2], [3, [[4]]]])
);
=> [ 1, 2, 3, 4 ]

without: 去掉元素

console.log(
_.without([1, 2, 1, 0, 3, 1, 4], 0,1 )
);
=> [ 2, 3, 4 ]

union,intersection,difference,uniq: 並集，交集，差集，取惟一

console.log(_.union([1, 2, 3], [101, 2, 1, 10], [2, 1]));
console.log(_.intersection([1, 2, 3], [101, 2, 1, 10], [2, 1]));
console.log(_.difference([1, 2, 3, 4, 5], [5, 2, 10]));
console.log(_.uniq([1, 2, 1, 3, 1, 2]));
=> [ 1, 2, 3, 101, 10 ]
[ 1, 2 ]
[ 1, 3, 4 ]
[ 1, 2, 3 ]

zip: 合併多個數組中的元素，是group的反向操做

console.log(
_.zip(['moe', 'larry', 'curly'], [30, 40, 50], [true, false, false])
);
=> [ [ 'moe', 30, true ],
[ 'larry', 40, false ],
[ 'curly', 50, false ] ]

object: 把數組轉換成對象

console.log(
_.object(['moe', 'larry', 'curly'], [30, 40, 50])
);
=> { moe: 30, larry: 40, curly: 50 }

三、函數部分

新建一個function.js

~ vi function.js
var _ = require("underscore")._;

bind: 綁定函數到對象上, 不管什麼時候函數被調用, 函數裏的this都指向對象.

var func = function(greeting){ return greeting + ': ' + this.name };
func = _.bind(func, {name : 'moe'}, 'hi');
console.log(func());
=> hi: moe

bindAll: 綁定方法名到對象上, 當這些方法被執行時將在對象的上下文執行. 綁定函數用做事件處理時很是方便, 不然函數調用時 this 關鍵字根本沒什麼用.

var buttonView = {
label : 'underscore',
onClick : function(){ console.log('clicked: ' + this.label); },
onHover : function(){ console.log('hovering: ' + this.label); }
};
var func = _.bindAll(buttonView, 'onClick', 'onHover');
func.onClick();
=> clicked: underscore

partial:在不改變this的狀況下，經過參數填充數據

var add = function(a, b) { return a + b; };
add5 = _.partial(add, 5);
console.log(add5(10));
=> 15

memoize: 經過緩存計算結果使函數具備記憶功能。

var fibonacci = _.memoize(function(n) {
return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);
});
console.log(fibonacci(10));
=> 55

delay: 在等待xx毫秒以後調用函數，相似於setTimeout

var log = _.bind(console.log, console);
_.delay(log, 1000, 'sleep 1s');
=> sleep 1s

defer: 延遲調用函數, 直到當前調用棧被清空爲止, 跟使用 setTimeout 賦予0毫秒的延時很像. 對執行高消耗算法或大型HTML呈現而不阻礙UI更新線程頗有用.

_.defer(function(){ console.log('deferred'); });
=> deferred

throttle:返回一個相似於節流閥同樣的函數, 當高頻率的調用函數, 實際上會每隔 wait 毫秒纔會調用一次. 對於高到您感受不到的高頻率執行的函數時很是有用.

var throttled = _.throttle(function(){
_(5).times(function(n){ console.log(n+":"+new Date()); });
}, 100);
throttled();
=> 0:Wed Aug 28 2013 14:20:48 GMT+0800
1:Wed Aug 28 2013 14:20:48 GMT+0800
2:Wed Aug 28 2013 14:20:48 GMT+0800
3:Wed Aug 28 2013 14:20:48 GMT+0800
4:Wed Aug 28 2013 14:20:48 GMT+0800

debounce: 返回函數的防反跳版本, 將延遲函數的執行(真正的執行)在函數最後一次調用時刻的等待xx毫秒以後，能夠實現延遲加載。

var lazyLoad = _.debounce(function(){
console.log("lazy load 3s");
}, 3000);
lazyLoad();
=> lazy load 3s

once: 建立一個只能運行一次的函數. 重複調用此修改過的函數會沒有效果, 只會返回第一次執行時返回的結果。單例模式。

var initialize = _.once(function(){console.log('initialize');});
initialize();
initialize();
=> initialize

after: 對循環計數，只有超過計數，纔會調用指定的函數

var nums = [1,2,3,4];
var renderNums = _.after(nums.length, function(){
console.log('render nums');
});
_.each(nums, function(num) {
console.log('each:'+num);
renderNums();
});
=> each:1
each:2
each:3
each:4
render nums

wrap: 以函數做爲函數傳遞，能夠增長函數調用先後的控制。有點相似於「模板方法模式」

var hello = function(name) { return "hello: " + name; };
hello = _.wrap(hello, function(func) {
return "before, " + func("moe") + ", after";
});
console.log(hello());
=> before, hello: moe, after

compose: 組合函數調用關係，把單獨的f(),g(),h()組合成f(g(h()))

var greet = function(name){ return "A: " + name; };
var exclaim = function(statement){ return "B: "+statement + "!"; };
var welcome = _.compose(exclaim, greet);
console.log(welcome('moe'));
=> B: A: moe!

四、對象部分

新建一個object.js

~ vi object.js
var _ = require("underscore")._;

keys,values,paris,invert: 取屬性名，取屬性值，把對象轉換成[key,value]數組，對調鍵值

var obj = {one: 1, two: 2, three: 3}
console.log(_.keys(obj));
console.log(_.values(obj));
console.log(_.pairs(obj));
console.log(_.invert(obj));
=> [ 'one', 'two', 'three' ]
[ 1, 2, 3 ]
[ [ 'one', 1 ], [ 'two', 2 ], [ 'three', 3 ] ]
{ '1': 'one', '2': 'two', '3': 'three' }

functions：返回對象的全部方法名

var fun = {
fun1:function(){},
fun2:function(){}
}
console.log(_.functions(fun));
=> [ 'fun1', 'fun2' ]

extend: 複製對象的全部屬性到目標對象上，覆蓋已有屬性

console.log(
_.extend({name : 'moe'}, {age : 50})
);
=> { name: 'moe', age: 50 }

defaults: 複製對象的全部屬性到目標對象上，跳過已有屬性

var iceCream = {flavor : "chocolate"};
console.log(
_.defaults(iceCream, {flavor : "vanilla", sprinkles : "lots"})
);
=> { flavor: 'chocolate', sprinkles: 'lots' }

pick,omit: 返回一個對象的副本，保留指定的屬性或去掉指定的屬性

console.log(
_.pick({name : 'moe', age: 50, userid : 'moe1'}, 'name', 'age')
);
=> { name: 'moe', age: 50 }
console.log(
_.omit({name : 'moe', age : 50, userid : 'moe1'}, 'userid')
);
=> { name: 'moe', age: 50 }

clone: 引入方式克隆對象，不進行復制

console.log(
_.clone({name : 'moe'});
);
=> {name : 'moe'};

tag: 用對象做爲參數來調用函數，做爲函數鏈式調用的一環

console.log(
_.chain([1,2,3,200])
.filter(function(num) { return num % 2 == 0; })
.tap(console.log)
.map(function(num) { return num * num })
.value()
);
=> [ 2, 200 ]
[ 4, 40000 ]

has: 判斷對象是否包含指定的屬性名

console.log(_.has({a: 1, b: 2, c: 3}, "b"));

isEqual: 判斷兩個對象是值相等

var moe = {name : 'moe', luckyNumbers : [13, 27, 34]};
var clone = {name : 'moe', luckyNumbers : [13, 27, 34]};
console.log(moe == clone);
=> false
console.log(_.isEqual(moe, clone));
=> true

判斷對象類型的方法，下面反回值都是true

console.log(_.isEmpty({}));
console.log(_.isArray([1,2,3]));
console.log(_.isObject({}));
console.log((function(){ return _.isArguments(arguments); })(1, 2, 3));
console.log(_.isFunction(console.log));
console.log(_.isString("moe"));
console.log(_.isNumber(8.4 * 5));
console.log(_.isFinite(-101));
console.log(_.isBoolean(true));
console.log(_.isDate(new Date()));
console.log(_.isNaN(NaN));
console.log(_.isNull(null));
console.log(_.isUndefined(undefined));
=> true

五、實用功能

新建一個util.js

~ vi util.js
var _ = require("underscore")._;

noConflict: 把「_」變量的控制權預留給它原有的全部者. 返回一個引用給 Underscore 對象.

var underscore = _.noConflict();

identity: 返回與傳入參數相等的值. 至關於數學裏的: f(x) = x

var moe = {name : 'moe'};
console.log(moe === _.identity(moe));
=> true

times: 設計調用次數

_(3).times(function(n){ console.log(n); });
=> 0
1
2

random: 返回範圍內的隨機數

console.log(_.random(0, 100));
=> 30

mixin: 封裝本身的函數到Underscore對象中，後面Underscore.string就是這種方式的集成

_.mixin({
capitalize : function(string) {
return string.charAt(0).toUpperCase() + string.substring(1).toLowerCase();
}
});
console.log(_("fabio").capitalize());
=> Fabio

uniqueId:產生一個全局的惟一id，以參數做爲前綴

console.log(_.uniqueId('contact_'));
=> contact_1
console.log(_.uniqueId('contact_'));
=> contact_2

escape,unescape:轉義HTML字符串，反轉到HTML字符串

console.log(_.escape('Curly, Larry & Moe'));
=> Curly, Larry & Moe
console.log(_.unescape('Curly, Larry & Moe'));
=> Curly, Larry & Moe

result: 經過字符串調用對象的函數，或返回屬性值

var obj = {cheese: 'crumpets', stuff: function(){ return 'nonsense'; }};
console.log(_.result(obj, 'cheese'));
=> crumpets
console.log(_.result(obj, 'stuff'));
=> nonsense

template: 將 JavaScript 模板編譯爲能夠用於頁面呈現的函數, 對於經過JSON數據源生成複雜的HTML並呈現出來的操做很是有用. 模板函數能夠經過如下兩種方式插入到頁面中, 使用<%= … %>, 也能夠用<% … %>執行任意的 JavaScript 代碼. 若是您但願插入一個值, 並讓其進行HTML轉義, 當您使用建立一個模板時使用 <%- … %> , 傳入一個含有與模板對應屬性的對象 data. 若是您要寫一個一次性的, 您能夠傳對象 data 做爲第二個參數給模板template 來直接呈現, 這樣頁面會當即呈現而不是返回一個模板函數. 參數 settings 是一個哈希表包含任何能夠覆蓋的設置 _.templateSettings.

var compiled = _.template("hello: <%= name %>");
console.log(compiled({name : 'moe'}));
=>hello: moe
var list = "<% _.each(people, function(name) { %> <li><%= name %></li> <% }); %>";
console.log(_.template(list, {people : ['moe', 'curly', 'larry']}));
=> <li>moe</li> <li>curly</li> <li>larry</li>
var template = _.template("<b><%- value %></b>");
console.log(template({value : '<script>'}));
=> <b><script></b>
var compiled = _.template("<% print('Hello ' + epithet); %>");
console.log(compiled({epithet: "stooge"}));
=>Hello stooge
console.log(_.template("Using 'with': <%= data.answer %>", {answer: 'no'}, {variable: 'data'}));
=>Using 'with': no
_.templateSettings = {
interpolate : /\{\{(.+?)\}\}/g
};
var template = _.template("Hello {{ name }}!");
console.log(template({name : "Mustache"}));
=>Hello Mustache!

六、鏈式語法

新建一個chaining.js

~ vi chaining.js
var _ = require("underscore")._;

chain: 返回一個封裝的對象. 在封裝的對象上調用方法會返回封裝的對象自己, 直到value() 方法調用爲止.

var stooges = [{name : 'curly', age : 25}, {name : 'moe', age : 21}, {name : 'larry', age : 23}];
var youngest = _.chain(stooges)
.sortBy(function(stooge){ return stooge.age; })
.map(function(stooge){ return stooge.name + ' is ' + stooge.age; })
.first()
.value();
console.log(youngest);
=> moe is 21

對一個對象使用 chain 方法, 會把這個對象封裝並讓之後每次方法的調用結束後都返回這個封裝的對象, 當您完成了計算, 可使用 value 函數來取得最終的值. 如下是一個同時使用了 map/flatten/reduce 的鏈式語法例子, 目的是計算一首歌的歌詞裏每個單詞出現的次數.

var lyrics = [
{line : 1, words : "I'm a lumberjack and I'm okay"},
{line : 2, words : "I sleep all night and I work all day"},
{line : 3, words : "He's a lumberjack and he's okay"},
{line : 4, words : "He sleeps all night and he works all day"}
];
console.log(
_.chain(lyrics)
.map(function(line) { return line.words.split(' '); })
.flatten()
.reduce(function(counts, word) {
counts[word] = (counts[word] || 0) + 1;
return counts;
}, {})
.value()
);
=> { 'I\'m': 2,
a: 2,
lumberjack: 2,
and: 4,
okay: 2,
I: 2,
sleep: 1,
all: 4,
night: 2,
work: 1,
day: 2,
'He\'s': 1,
'he\'s': 1,
He: 1,
sleeps: 1,
he: 1,
works: 1 }

value: 提取封裝對象的最終值，做爲chain()結束標誌。

console.log(_([1, 2, 3]).value());

七、字符串處理Underscore.String

安裝underscore.string

~ D:\workspace\javascript\nodejs-underscore>npm install underscore.string
npm http GET https://registry.npmjs.org/underscore.string
npm http 304 https://registry.npmjs.org/underscore.string
underscore.string@2.3.3 node_modules\underscore.string

新建一個string.js，經過mixin()函數,讓underscore.string和underscore集成統計實現_.fun()語法。

~ vi string.js
var _ = require('underscore');
_.str = require('underscore.string');
_.mixin(_.str.exports());

字符串的數字格式化

console.log(_.numberFormat(1000, 2));
=> 1,000.00
console.log(_.numberFormat(123456789.123, 5, '.', ','));
=> 123,456,789.12300
console.log(_('2.556').toNumber());
=> 3
console.log(_('2.556').toNumber(2));
=> 2.56
console.log(_.sprintf("%.1f", 1.17));
=> 1.2

字符串基礎操做

console.log(_.levenshtein('kitten', 'kittah'));
=> 2
console.log(_.capitalize('epeli'));
=> Epeli
console.log(_.chop('whitespace', 3));
=> [ 'whi', 'tes', 'pac', 'e' ]
console.log(_.clean(" foo bar "));
=> foo bar
console.log(_.chars('Hello'));
=> [ 'H', 'e', 'l', 'l', 'o' ]
console.log(_.swapCase('hELLO'));
=> Hello
console.log(_.str.include("foobar", "ob")); //不兼容API，須要用_.str.fun()
=> true
console.log(_.str.reverse("foobar"));//不兼容API，須要用_.str.fun()
=> raboof
console.log(_('Hello world').count('l'));
=> 3
console.log(_('Hello ').insert(6, 'world'));
=> Hello world
console.log(_('').isBlank() && _('\n').isBlank() && _(' ').isBlank());
=> true
console.log(_.join(",", "foo", "bar"));
=> foo,bar
console.log(_.lines("Hello\nWorld"));
=> [ 'Hello', 'World' ]
console.log(_("image.gif").startsWith("image"));
=> true
console.log(_("image.gif").endsWith("gif"));
=> true
console.log(_('a').succ());//指下編碼的下一個
=> b

字符串變換

console.log(_.repeat("foo", 3));
=> foofoofoo
console.log(_.repeat("foo", 3, "bar"));
=> foobarfoobarfoo
console.log(_.surround("foo", "ab"));
=> abfooab
console.log(_.quote('foo', "#"));
=> #foo#
console.log(_.unquote('"foo"'));
=> foo
console.log(_.unquote("'foo'", "'"));
=> foo
console.log(_.slugify("Un éléphant à l'orée du bois"));
=> un-elephant-a-loree-du-bois
console.log(['foo20', 'foo5'].sort(_.naturalCmp));
=> [ 'foo5', 'foo20' ]
console.log(_.toBoolean("true"));
=> true
console.log(_.toBoolean("truthy", ["truthy"], ["falsy"]));
=> true
console.log(_.toBoolean("true only at start", [/^true/]));
=> true

字符串替換,截斷

console.log(_('https://edtsech@bitbucket.org/edtsech/underscore.strings').splice(30, 7, 'epeli'));
=> https://edtsech@bitbucket.org/epeli/underscore.strings
console.log(_.trim(" foobar "));
=> foobar
console.log(_.trim("_-foobar-_", "_-"));
=> foobar
console.log(_('Hello world').truncate(5));
=> Hello...
console.log(_('Hello, world').prune(5));
=> Hello...
console.log(_('Hello, world').prune(5, ' (read a lot more)'));
=> Hello, world
console.log(_.words(" I love you "));
=> [ 'I', 'love', 'you' ]
console.log(_.words("I-love-you", /-/));
=> [ 'I', 'love', 'you' ]
console.log(_('This_is_a_test_string').strRight('_'));
=> is_a_test_string
console.log(_('This_is_a_test_string').strRightBack('_'));
=> string
console.log(_('This_is_a_test_string').strLeft('_'));
=> This
console.log(_('This_is_a_test_string').strLeftBack('_'));
=> This_is_a_test

字符串佔位

console.log(_.pad("1", 8));
=> 1
console.log(_.pad("1", 8, '0'));
=> 00000001
console.log(_.pad("1", 8, '0', 'right'));
=> 10000000
console.log(_.pad("1", 8, 'bleepblorp', 'both'));
=> bbbb1bbb
console.log(_.lpad("1", 8, '0'));
=> 00000001
console.log(_.rpad("1", 8, '0'));
=> 10000000
console.log(_.lrpad("1", 8, '0'));
=> 00001000

字符串語義處理

console.log(_.toSentence(['jQuery', 'Mootools', 'Prototype']));
=> jQuery, Mootools and Prototype
console.log(_.toSentence(['jQuery', 'Mootools', 'Prototype'], ', ', ' unt '));
=> jQuery, Mootools unt Prototype
console.log(_.toSentenceSerial(['jQuery', 'Mootools']));
=> jQuery and Mootools
console.log(_.toSentenceSerial(['jQuery', 'Mootools', 'Prototype']));
=> jQuery, Mootools, and Prototype
console.log(_('my name is epeli').titleize());
=> My Name Is Epeli
console.log(_('-moz-transform').camelize());
=> MozTransform
console.log(_('some_class_name').classify());
=> SomeClassName
console.log(_('MozTransform').underscored());
=> moz_transform
console.log(_('MozTransform').dasherize());
=> -moz-transform
console.log(_(' capitalize dash-CamelCase_underscore trim ').humanize());
=> Capitalize dash camel case underscore trim

HTML相關操做

console.log(_('<div>Blah blah blah</div>').escapeHTML());
=> <div>Blah blah blah</div>
console.log(_('<div>Blah blah blah</div>').unescapeHTML());
=><div>Blah blah blah</div>
console.log(_('a <a href="#">link</a>').stripTags());
=>a link
console.log(_('a <a href="#">link</a><script>alert("hello world!")</script>').stripTags());
=>a linkalert("hello world!")