摘要：
JavaScript is a bit confusing for developers experienced in class-based languages (like Java or C++), as it is dynamic and does not provide a class im 阅读全文
摘要：
七种数据类型 ·Symbol ·undefined ·null ·Boolean ·String ·Number ·Object let a = Symbol('this is a symbol'); let b = Symbol(); console.log(a b); //false Symbo 阅读全文