ES6 -- object

Tips ： When the article is finished , Directories can be generated automatically , How to generate it, please refer to the help document on the right

List of articles

Catalog

List of articles

1. Concise representation of object attributes

 2. Shorthand for object methods

3. The attribute expression of an object

 4. New methods of object

---

1. Concise representation of object attributes

            var count=20
            var obj={count}  //es6 Object members of can be written as   A word   This word is the variable name : Take the variable name as the attribute name of the object   Value is taken as the attribute value ( Easy to read , Improve the development effect )

            var {age}={age:20}
            console.log(obj["count"]) 

var obj={count:count}   <==>   {"count":count}   // Two ways to write object members , Equal writing

Running results ：

 2. Shorthand for object methods

Method shorthand : Functions have many nicknames according to business : Constructors Static functions Method Event handler ( Monitor )   Closure   Callback function Hook function

        var obj = {

                name: "karen",

                say: function() { }

              }

       //name and say All are obj Object members   name yes obj Properties of (pro) say It's the object obj Methods

        var obj2 = {

                name: "jack",

                say() { }        //say(){ } Method shorthand , And the above   say: function() {  } equal

            }

3. The attribute expression of an object

            var obj = {
				name: "karen",      // Commonly used writing 
				"age":20,           // Standard writing ,
				["hello"+100]:90,   //es6 How to write it 
				[false]:90,         //es6 How to write it 
				[{life:100}]:90,    //es6 How to write it ,
				[Symbol(100)]:200
			}
			console.log(obj)

Running results ：

  When two objects have the same properties , Those with the same name will be overwritten , The back one will cover the front one .

Extension operators （...） Used to extract all traversable properties of the parameter object and copy it to the current object

            var obj={name:"karen",age:20,arr:[10,20],life:2}
			var obj3={life:7,x:100}

			var obj2={life:80,...obj,life:100,...obj3}
			console.log(obj2)
			console.log(obj2,obj==obj2,obj.arr==obj2.arr)

Running results ：

 4. New methods of object

        Object.is(value1, value2)： Used to compare whether two values are strictly equal , And （===） similar .

            var a=-0
			var b=+0
			var re=Object.is(a,b)    // Namely ===  Made a little adjustment 
			console.log(re,a===b)
			
			
			var re=(["10"]==10)
			console.log(re)

Running results ：