1. Let and block-level scope
JS scope: global scope, function scope. There is no concept of block scope. Block-level scopes are new in ECMAScript 6. Block scopes are included by {}. The {} in the if and for statements are also block scopes.
var elements = [{}, {}, {}]; for (var i=0; i < elements.length; i++) { elements[i].onclick = function() { console.log(i); } } elements[1].onclick(); //// PS F:\ lagou> node.\task1\task1.js 3 3 3Copy the code1.1 Through closures
var elements = [{}, {}, {}]; for (var i = 0; i < elements.length; i++) { elements[i].onclick = (function (i) { return function () { console.log(i); } })(i) } elements[0].onclick(); elements[1].onclick(); elements[2].onclick(); //// PS F:\ lagou> node.\task1\task1.js 0 1 2Copy the code1.2 use the let
var elements = [{}, {}, {}]; for (let i = 0; i < elements.length; i++) { elements[i].onclick = function () { console.log(i); } } elements[0].onclick(); elements[1].onclick(); elements[2].onclick(); //// PS F:\ lagou> node.\task1\task1.js 0 1 2Copy the code2. Array deconstruction
Const arr = [100200300]; const [a,b,c] = arr; console.log(a,b,c); //// PS F:\ lagou> node.\task1\task1.js 100 200 300Copy the code2.1 Defining only one variable requires leaving other positions empty
Const arr = [100200300]; const [,,c] = arr; console.log(c); //// PS F:\ lagou> node.\task1\task1.js 300Copy the code2.2 use… Define the remaining variables
It can only be defined in the last position
Const arr = [100200300]; const [a, ...rest] = arr; console.log(rest); //// PS F:\ lagou> node.\task1\task1.js [200, 300]Copy the codeConst arr = [100200300]; const [...rest] = arr; console.log(rest); //// PS F:\ lagou> node.\task1\task1.js [100, 200, 300]Copy the codeConst arr = [100200300]; const [...rest,c] = arr; console.log(rest); / / / / F: \ retractor front-end \ lagou \ task1 \ task1 js: 15 const /... rest, c = arr; ^ ^ ^ ^ ^ ^ ^Copy the code2.3 Assign initial values during deconstruction
const arr = [100, 200, 300]; const [a, b, c = 123, d = 'defaultValue'] = arr; console.log(c, d); //// PS F:\ lagou> node.\task1\task1.js 300 defaultValueCopy the code2.4 Deconstruction example: Parse the path
// Const path = '/foo/bar/baz'; const temp = path.split('/'); const rootdir = temp[1]; console.log(temp); console.log(rootdir); / / / / PS F: \ retractor front-end \ lagou > node. \ task1 \ task1 js [' and 'foo', 'bar', 'baz'] fooCopy the code// const path = '/foo/bar/baz'; const [,rootdir] = path.split('/'); console.log(rootdir); //// PS F:\ lagou> node.\task1\task1.js fooCopy the code3. Deconstruction of objects
3.1 Objects are defined by keys and arrays by subscripts
const obj = {name:'yangzhen' , age:24}; const { name , age , sex } = obj; console.log(sex,name,age); //// PS F:\ lagou> node.\task1\task1.js undefined yangzhen 24Copy the code3.2 Do not Use aliases
const obj = {name:'yangzhen' , age:24};
const name = 'jack';
const { name , age , sex } = obj;
console.log(sex,name,age);
////
const { name , age , sex } = obj;
^
SyntaxError: Identifier 'name' has already been declared
Copy the code3.3 Assigning an Initial Value using an Alias
const obj = {name:'yangzhen' , age:24}; const name = 'jack'; const { name:myname , age , sex = 18 } = obj; console.log(sex,myname,age); //// PS F:\ lagou> node.\task1\task1.js 18 Yangzhen 24Copy the code4. String extension methods
const { log } = console
const message = 'Error: foo is noe defined.'
log (
message.startsWith('Error'),
message.endsWith('.'),
message.includes('is')
)
////
true true true
Copy the code5. Default values of function parameters
5.1 Primitive Methods (for Boolean types)
Function foo(enable) {// Primitive method (for Boolean types) enable = enable === undefined? true : false console.log(enable) } foo() //// true foo(false) //// falseCopy the code5.2 Primitive Methods (for other types)
/ / function parameter of the default function foo (enable) {/ / original methods enable = enable | | 0 console. The log (enable)} foo () / / / / 0 foo (5) / / / / 5Copy the code5.3 ES6 grammar
function foo(enable = true){
console.log(enable)
}
foo() //// true
foo(false) //// false
Copy the code6. Remaining parameters
6.1 Method 1: Use Arguments
Function foo(){console.log(arguments)} foo(1,2,3,4) //// PS E:\lagou front-end \demo> node.\part1\test1.js [arguments] {'0': 1, '1': 2, '2': 3, '3': 4}Copy the codeFunction foo(){const [a,b,c,d] = arguments console.log(a,b,c,d)} foo('a',2,3,4) //// PS E:\lagou front-end \demo> node .\part1\test1.js a 2 3 4Copy the code6.2 Method 2: Using…
. Args can only be used once at the end
function foo(first,... Args){console.log(first) console.log(args)} foo('a',2,3,4) //// PS E:\lagou front-end \demo> node.\part1\test1.js a [2,3, 4]Copy the code6.3 ·· Expand the array
Const arr = [1,2,3,4] console.log(... Arr) //// PS E:\lagou front-end \demo> node.\part1\test1.js 1 2 3 4Copy the code7. Arrow function and this
Normal functions: the direction of this is not determined when the function is created, but only when the function is called.
The arrow function has no prototype, so the arrow function itself has no this. The this inside the arrow function is lexical scoped, depending on the context, and refers to this, which at definition inherits from the first normal function in the outer layer. The this object inside the function is the object at which it is defined, regardless of the object at which it is used.
const name = 'jack' const person = { name: 'tom', sayHi: Function (){console.log(' my name is ${this.name} ')}} person.sayhi () //// PS E:\lagou front-end \demo> node.part1 \test1.js my name is tomCopy the codeconst name = 'jack' const person = { name: 'tom', sayHi: Function (){console.log(' my name is ${name} ')}} person.sayhi () //// PS E:\lagou front-end \demo> node.part1 \test1.js my name is jackCopy the code7.1 Using the arrow function
The arrow function does not change the direction of this
Const person = {name: 'Tom ', sayHi: () => {console.log(' my name is ${this.name} ')}} person.sayhi () //// PS E:\lagou front-end \demo> node.part1 \test1.js my name is undefinedCopy the codeconst name = 'jack' const person = { name: 'tom', sayHi: () => { console.log(`my name is ${name}`) } } console.log(this) console.log(this.name) person.sayHi() //// PS E:\lagou front-end \demo> node.\part1\test1.js {} undefined my name is jackCopy the code7.2 Traditional _this Usage
const person = { name: 'tom', sayHi: function() { console.log(`my name is ${this.name}`) }, sayHiAsync:function(){ setTimeout(function () { console.log(`my name is ${this.name}`) }, 1000); }} person.sayhi () person.sayhiasync () //// PS E:\lagou front-end \demo> node.part1 \test1.js My name is Tom my name is undefinedCopy the codeconst person = { name: 'tom', sayHi: function() { console.log(`my name is ${this.name}`) }, sayHiAsync:function(){ _this = this; setTimeout(function () { console.log(`my name is ${_this.name}`) }, 1000); }} person.sayhi () person.sayhiasync () //// PS E:\lagou front-end \demo> node.part1 \test1.js My name is Tom my name is TomCopy the code7.3 setTimeout Using the arrow function can avoid _this
The this inside the arrow function is lexical scoped, determined by context
const person = { name: 'tom', sayHi: () => { console.log(`my name is ${this.name}`) }, sayHiAsync:function(){ setTimeout(()=> { console.log(`my name is ${this.name}`) }, 1000); }} person.sayhi () person.sayhiasync () //// PS E:\lagou front-end \demo> node.part1 \test1.js my name is undefined my name is tomCopy the code8. Object literals are enhanced
const bar = '345' const obj = { foo: 123, //bar:bar bar, //method1:function(){ // console.log(this) //} method1(){ console.log(this) }, [math.random ()]:456} // In traditional methods, Object dynamically adds property obj[math.random ()] = 123 console.log(obj) obj.method1() //// PS E:\lagou front-end \demo> node.\part1\test1.js {foo: {foo: 123, bar: '345', method1: [Function: method1], '0.8616180359346404': 123} {foo: 123, bar: '345', method1: [Function: Method1], '0.8616180359346404' : 123}Copy the code9. Object extension method
9.1 Object.assignCopies properties from multiple source objects to the target object
const source1 = { a:123, b:123 } const source2 = { b:789, d:789 } const target = { a:456, c:456 } const result = Object.assign(target,source1,source2) console.log(target) console.log(result === target) //// PS E:\lagou front-end \demo> node.\part1\test1.js {a: 123, C: 456, b: 789, d: 789} trueCopy the code9.2 case
function func(obj){
obj.name = 'func obj'
console.log(obj)
}
const obj = {name: 'global obj'}
func(obj)
console.log(obj)
////
{ name: 'func obj' }
{ name: 'func obj' }
Copy the codefunction func(obj){
const funObj = Object.assign({},obj)
funObj.name = 'func obj'
console.log(funObj)
}
const obj = {name: 'global obj'}
func(obj)
console.log(obj)
////
{ name: 'func obj' }
{ name: 'global obj' }
Copy the code10. Proxy Proxy object
const person = { name: 'yang', age: // Parameter 1: Proxy object // Parameter 2: Proxy object const personProxy = new Proxy(person,{// Get method to monitor attribute access // parameter 1: Proxy target object // parameter 2: attribute name accessed externally get(target,property){ console.log(target,property) return 100 }, Set (){}}) console.log(personproxy.name) //// PS E:\lagou front-end \demo> node.\part1\test1.js {name: 'yang', age: 18 } name 100Copy the codeconst person = { name: 'yang', age: // Parameter 1: Proxy object // Parameter 2: Proxy object const personProxy = new Proxy(person,{// Get method to monitor attribute access // parameter 1: Proxy target object // parameter 2: attribute name accessed externally get(target,property){ return property in target ? target[property] : 'default' }, Set (){}}) console.log(personproxy.name) console.log(personproxy.xxxx) //// PS E:\lagou front-end \demo> node .\part1\test1.js yang defaultCopy the codeconst person = { name: 'yang', age: // Parameter 1: Proxy object // Parameter 2: Proxy object const personProxy = new Proxy(person,{// Get method to monitor attribute access // parameter 1: Proxy target object // parameter 2: attribute name accessed externally get(target,property){ return property in target ? Target [property] : 'default'}, // Use the set method to set the property //1. Set (target,property,value){if(property === 'age') {if(! Number.isInteger(value)) { throw new TypeError(`${value} is not an int`) } } target[property] = value } }) Personproxy.age = 30 personproxy.sex = 'man' console.log(personProxy) //// PS E:\lagou front-end \demo> node.\part1\test1.js { name: 'yang', age: 30, sex: 'man' }Copy the code11. The proxy and the Object. DefineProperty ()
11.1 Object.defineProperty() can only listen for reads and writes of objects
const person = { name: 'yang', age: 18 } const personProxy = new Proxy(person,{ deleteProperty(target,property){ console.log('delete',property) delete Target [property]}}) delete personproxy.age console.log(person) //// PS E:\lagou front-end \demo> node.\part1\test1.js delete age { name: 'yang' }Copy the code11.2 Proxy better supports array object monitoring
const list = [] const listProxy = new Proxy(list,{ set(target,property,value) { console.log('set',property,value) Target [property] = value return true}}) listproxy.push (100) Listproxy.push (200) Console. log('list',list) //// PS E:\lagou front-end \demo> node. \part1\test1.js set 0 100 set length 1 set 1 200 set length 2 list [ 100, 200 ]Copy the code12.Reflect unified object manipulation API
A static class that encapsulates a set of low-level operations on an object
The Reflet member method is the default implementation of Proxy handling objects
12.1 remove the Reflect
const person = { name: 'yang', age: 18 } const personProxy = new Proxy(person,{ get(target,property) { console.log('watch logic') // return Reflect.get(target,property)}}) console.log(personproxy.age) //// PS E:\lagou front-end \demo> node.\part1\test1.js watch logic undefinedCopy the code12.2 add Reflect
const person = { name: 'yang', age: 18 } const personProxy = new Proxy(person,{ get(target,property) { console.log('watch logic') return Reflect.get(target,property)}}) console.log(personproxy.age) //// PS E:\lagou front-end \demo> node.\part1\test1.js watch logic 18Copy the codeReflect does what it does: Provide a unified set of apis for manipulating objects
12.3 Not Using Reflect’s Operation on an Object
const person = { name: 'yang', age: Log ('name' in person) // Get all the Key console.log(object.keys (person)) // delete the properties of the Object Console. log(delete person['age']) console.log(person) //// PS E:\lagou front-end \demo> node.\part1\test1.js true [' name', 'age' ] true { name: 'yang' }Copy the code12.4 Operation on an Object Using Reflect
const person = { name: 'yang', age: Log (reflect. has(person,'name')) // Get all the Key console.log(reflect.ownkeys (person)) // delete the property of the object Console. log(Reflect. DeleteProperty (person,'age')) console.log(person) //// PS E:\lagou front-end \demo> node.\ part1\test1.js true [ 'name', 'age' ] true { name: 'yang' }Copy the codePromise a better asynchronous programming solution
It solves the problem of function nesting too deeply in traditional asynchronous programming
14. The class keyword
14.1 Traditional Use of Prototype
function Person (name) { this.name = name; } Person.prototype.say = function () { console.log(`my name is ${this.name}`) } const p = new Person('tom') p.say() //// PS E:\lagou front-end \demo> node.\part1\test1.js my name is TomCopy the code14.2 use the class
class Person { constructor(name) { this.name = name } say() { console.log(`my name is ${this.name}`) } } const p = new Person(' Tom ') p.say() //// PS E:\lagou front-end \demo> node.\part1\test1.js My name is TomCopy the code14.3 Static methods
class Person { constructor(name) { this.name = name } say() { console.log(`my name is ${this.name}`) } static Create (name) {return new Person(name)}} const p = person.create (' Tom ') p.say() //// PS E:\lagou front-end \demo> node .\part1\test1.js my name is tomCopy the code14.4 inheritance
class Person { constructor(name) { this.name = name } say() { console.log(`my name is ${this.name}`) } static create(name) { return new Person(name) } } class Student extends Person { constructor(name,number) { super(name) this.number = number } hello() { super.say() console.log(`my number is ${this.number}`) } } const s = new Student(' Jack ',100) s.hollo () //// PS E:\lagou front-end \demo> node.\ part1\test1.js My name is jack my number is 100Copy the code15.Set data type
Const s = new Set() //add returns Set so we can chain s.addd (1).add(2).add(3).add(4).add(4).add(5 console.log(s) //// Set { 1, 2, 3, 4, Log (I => {console.log(I) //// 1 2 3 4 5}) console.log(s.size) //// 5 console.log(s.has(100)) ////false console.log(s.delete(3)) ////true console.log(s) //// Set { 1, 2, 4, 5 }Copy the code15.1 Array deprocessing by Set
Array.from() converts a Set to an Array
Const result = [1,2,3,1,2,1,4,1] //const result = array. from(new Set(arr)) const result = [...new Set(arr)] Console. log(result) PS E:\lagou front-end \demo> node.\part1\test1.js [1, 2, 3, 4]Copy the code16.Map data structure
16.1 Common Key-value pairs
The key of an object can only be a String. If the key is not a String, it is automatically converted to a String
const obj = {} obj[true] = 'value' obj[123] = 'value' obj[{ a: 1}] = 'value' console.log(object.keys (obj)) //// PS E:\lagou front-end \demo> node.\part1\test1.js ['123', 'true', '[object Object]' ]Copy the code16.2 the Map type
Const m = new Map() const Tom = {name:' Tom '} m.net (Tom,90) console.log(m) console.log(m.net (Tom)) //Map traversal M.foreach ((value,key)=>{console.log(value,key)}) //// PS E:\lagou front-end \demo> node.\part1\test1.js Map {{name: 'tom' } => 90 } 90 90 { name: 'tom' }Copy the code17.Symbol New data type
17.1 The primary function is to add unique attribute names to objects
Const s = Symbol() console.log(s) console.log(typeof s) console.log(Symbol() === Symbol())) Console. log(Symbol('foo')) //// PS F:\ lagou> node.\task1\task1.js Symbol() Symbol false Symbol(foo)Copy the code17.2 Setting Private Members of an Object
const name = Symbol(); const person = { [name]:'yang', Say (){console.log(this[name])}} console.log(person[Symbol()]) person.say() //// PS F:\ lagou front end \lagou> node .\task1\task1.js undefined yangCopy the code18. The for of circulation
Is a unified traversal of data
Const arr = [100,200,300,400,500] for (item of arr) {console.log(item) ////100 200 300 400 if(item > 300){break}} The arr.foreach (item =>{console.log(item) ////100 200 300 400}) //some() method is used to check whether the elements in the array satisfy the specified condition (provided by the function). The //some() method executes each element of the array in turn: // If one element meets the criteria, the expression returns true, and the rest of the elements are not checked. // If there is no element that meets the condition, return false. The every() method is used to check whether all elements of an array meet the specified criteria (provided by the function). The //every() method checks all elements in the array using the specified function: // If one element in the array is detected that is not satisfied, the entire expression returns false, and the rest of the elements are not tested. // Return true if all elements meet the criteria. const result = arr.some((item)=>{ return item > 300 }) console.log(result) ////true for (i in arr) { console.log(arr[i]) ////100 200 300 400 500}Copy the code18.1 Set for of traversal
Const s = new Set(['foo','bar']) for (const item of s) {console.log(item)} //// PS F:\ lagou> node .\task1\task1.js foo barCopy the code18.2 For of Traversal of Map
const m = new Map() m.set('foo','123') m.set('bar','456') for(const item of m ) { console.log(item) } //// PS F: \ retractor front-end \ lagou > node. \ task1 \ task1 js [' foo ', '123'] [' bar ', '456']Copy the code18.3 Use array deconstruction to obtain K V
const m = new Map() m.set('foo','123') m.set('bar','456') for(const [key,value] of m ) { console.log(key,value) } //// PS F:\ lagou> node.\task1\task1.js foo 123 bar 456Copy the code19. Implement Iterable interface
Objects cannot iterate directly
Hangs an iterator method that returns an iterator object
Interface convention: There must be an internal Next method for iteration
const obj = {
store: ['foo','bar','baz'],
[Symbol.iterator]: function() {
let index = 0
const self = this
return {
next: function() {
const result = {
value:self.store[index],
done:index >= self.store.length
}
index++
return result
}
}
}
}
for (const item of obj) {
console.log('循环',item)
}
////
PS F:\拉钩前端\lagou> node .\task1\task1.js
循环 foo
循环 bar
循环 baz
Copy the code20. Iterator pattern
20.1 Achieve the purpose of iterators
Scenario: Collaborate on a task list application
/ / = = = = = = = = = = = = = = my code = = = = = = = = = = = = = = const todos = {life: [' eating ', 'sleeping', 'play doug'], learn: [' language ', 'mathematics',' English ']. } / / = = = = = = = = = = = = = = your code = = = = = = = = = = = = = = the for (const item of todos. Life) {the console. The log (item)} for (const item of todos.learn){ console.log(item) }Copy the codeIf I need to add data to my toDOS data list, your code needs to change accordingly; it’s too coupled for the call
/ / = = = = = = = = = = = = = = my code = = = = = = = = = = = = = = const todos = {life: [' eating ', 'sleeping', 'play doug'], learn: [' language ', 'mathematics',' English ']. Work: [' singing ']} / / = = = = = = = = = = = = = = your code = = = = = = = = = = = = = = the for (const item of todos. Life) {the console. The log (item)} for (const item of todos.learn){ console.log(item) } for(const item of todos.work){ console.log(item) }Copy the code20.2 How can I Solve the problem
If my code can uniformly provide a traversal interface
For the caller, there is no need to worry about its internal data structure and no need to worry about structural changes
We can write a method to do this ourselves:
/ / = = = = = = = = = = = = = = my code = = = = = = = = = = = = = = const todos = {life: [' eating ', 'sleeping', 'play doug'], learn: [' language ', 'mathematics',' English '], the work: [' sing '], each: function (callback) { const all = [].concat(this.life, this.learn, This. Work) for (item of all) {callback (item)}}} / / = = = = = = = = = = = = = = your code = = = = = = = = = = = = = = todos. Each (function (item) { console.log(item); })Copy the code20.3 Implemented by iterator method
/ / = = = = = = = = = = = = = = my code = = = = = = = = = = = = = = const todos = {life: [' eating ', 'sleeping', 'play doug'], learn: [' language ', 'mathematics',' English '], the work: [' singing '], [Symbol. The iterator] : the function () {/ / using the object operator is equivalent to [] concat const all = [... this. Life,... this. Learn,... this. Work] let index = 0 return{ next:function(){ return{ value:all[index], done: Index++ > = all. Length / / true will be finished iteration}}}}} / / = = = = = = = = = = = = = = your code = = = = = = = = = = = = = = the for (item of todos) { Console. log(item)} //// PS F:\ lagou> node.\task1\task1.js Eat, sleep, play beans, language, Maths, English, singCopy the codeThe core of an iterator is to provide a unified traversal interface so that the external world doesn’t have to worry about what the internal data structure looks like
The each method shown here applies only to the array structure shown here
ES2015 iterators are iterator patterns implemented from the language level, so it is applicable to any data structure, as long as the implementation of the Iterable interface, then we can implement for… Of traverses the object
21. Generator functions
Solve the problem of asynchronous programming callbacks that are too deeply nested
function * foo(){
console.log('test')
return 100
}
const result = foo()
console.log(result)
console.log(result.next())
////
Object [Generator] {}
test
{ value: 100, done: true }
Copy the code21.1 Lazy execution of yield
function * foo(){
console.log('111')
yield 100
console.log('222')
yield 200
console.log('333')
yield 300
}
const generator = foo()
console.log(generator)
console.log(generator.next())
console.log(generator.next())
console.log(generator.next())
console.log(generator.next())
////
Object [Generator] {}
111
{ value: 100, done: false }
222
{ value: 200, done: false }
333
{ value: 300, done: false }
{ value: undefined, done: true }
Copy the code21.2 the Generator application
Case 1: transmitter
function * createIdMaker(){ let id = 1 while(true) { yield id++ } } const idMaker = createIdMaker() console.log(idMaker.next().value) console.log(idMaker.next().value) console.log(idMaker.next().value) Console. log(idmaker.next ().value) //// PS E:\lagou front-end \demo> node.\part1\test1.js 1 2 3 4Copy the codeCase 2: Implement Iterator methods using Generator functions
Const todos = {life: [' eating ', 'sleeping', 'play doug'], learn: [' language ', 'mathematics',' English '], work: [' singing '], [Symbol. The iterator] : function* () { const all = [...this.life, ...this.learn, ...this.work] for (item of all) { yield item } } } for (const item of todos) { console.log(item) } //// PS E:\lagou front-end \demo> node.\part1\test1.js eat, sleep, play beans, language, Maths, English, singCopy the code22.ES2016
22.1 Array. Prototype. Includes
Let’s first look at the indexOf method
const arr = ['foo',1,NaN,false] console.log(arr.indexOf('foo')) console.log(arr.indexOf(1)) Console. log(arr.indexof (NaN)) console.log(arr.indexof (false)) //// PS F: lagou> node.\task1\task1.js 0 1-3Copy the codeIndexOf cannot check for NaN
NaN is a special numeric value (the result of typeof NaN is number), which is short for not a number, indicating that it is not a valid number.
Note: NaN is the only value not equal to itself: NaN === NaN // false
22.2 includes checks that NaN returns a Boolean value
const arr = ['foo',1,NaN,false] console.log(arr.includes('foo')) console.log(arr.includes(1)) Console. log(arr.includes(NaN)) console.log(arr.includes(false)) //// PS F: lagou> node.\task1\task1.js true true true trueCopy the code22.3 Exponential operators
Console. log(math.pow (2,10)) console.log(2 ** 10) //// PS F:\ lagou> node.\task1\task1.js 1024 1024Copy the code23.ES2017
23.1 the Object values
const obj = { foo: 'value1', bar: 'balue2'} console.log(object.values (obj)) //// PS F:\ lagou> node.\task1\task1.js ['value1', 'balue2']Copy the code23.2 Object. Entries
Array returns key-value pairs
const obj = { foo: 'value1', bar: 'balue2'} console.log(object. entries(obj)) //// PS F:\ lagou> node.\task1\task1.js [['foo', 'value1'], [ 'bar', 'balue2' ] ]Copy the codeSo you can use “for of.
const obj = { foo: 'value1', bar: 'balue2' } for (const [key, value] of Object.entries(obj)) { console.log(key, Value)} //// PS F:\ lagou> node.\task1\task1.js foo value1 bar balue2Copy the codeConvert Map objects using entries
const obj = { foo: 'value1', bar: 'balue2'} console.log(new Map(object.entries (obj))) //// PS F:\ lagou> node.\task1\task1.js Map {'foo' => 'value1', 'bar' => 'balue2' }Copy the code