Class pattern and syntax in JS 2021.11.10

es6 Added class Kind of grammar , Like most object-oriented languages Use classes to generate objects , but es6 Of class Just a class syntax sugar , Formal grammar Simplified writing , Achieve parity , It's essentially a constructor + Patterns of prototype objects .

Constructors Used to create attributes , Prototype object setting method .

 // Constructors + Prototype object The structure is messy ,class Is to put them together , Give Way js More elegant object-oriented

It is written as follows ：

class Grammatical norms of ：

1、 Constructor has preload - Declaration upgrade , but class No, ;

2、class Inside , The default is the strict mode environment ;（es5 New strict mode , Is to put the code Put it in a safer place 、 Run in an efficient environment - Regular validation ）